Diana brother’s new love: Having MS was so non-public I hadn’t even informed Charles. I felt totally sick once I found Countess Spencer had been telling individuals about it behind my again

You don’t embark on a romantic relationship with someone as high profile as Charles Spencer, thrice-married brother of Princess Diana, without being aware that your deepest (and most carefully buried) secrets could end up in the public domain, the stuff of society gossip.

Dr Cat Jarman, TV archaeologist and the new woman in Earl Spencer’s life, thought her ‘big secret’ was safe, though. ‘I’d worked very hard at making sure it stayed a secret,’ she tells me. ‘For six years, I had gone to great lengths to keep it hidden. None of my TV colleagues knew. Even Charles did not know. When you have a new partner, you have to gauge when and how to tell them something this huge, and I hadn’t yet done so.’

This big secret? Well, it’s nothing scandalous or salacious, although it is deeply personal, in the way that medical matters are. Cat, who met Earl Spencer when taking part in an archaeological dig at his ancestral home of Althorp, takes a deep breath before revealing the details, fully aware of the irony that she is now ‘outing’ herself, putting this information in the public domain for the first time. Clearly, she feels this is the lesser evil.

‘I have Multiple Sclerosis,’ she explains. ‘I was diagnosed eight years ago, when I was in the final stages of doing my PhD. I woke one morning with crippling pins and needles, shooting pains in my spine, as if I was being Tasered. I completely lost the power of my right hand – I couldn’t even hold a pen. My body simply stopped working. It took nine months to be able to use my hand again. I’m now on strong medication, and everything is kept at bay, but the problem with MS is that you live not knowing if you are going to have a relapse. My body could just stop working again tomorrow. It could be my eyesight, or my legs, or anything, or I could be fine for the rest of my life. There is no way of knowing.’

She was ‘utterly devastated’. The diagnosis was life-changing (she actually changed her career path because of it, which we will return to), but at the time, because of the way people around her reacted to her illness (‘The general reaction was, “Oh, what a waste”’), she made the decision that she did not want her MS to be public knowledge. ‘I thought I would be discriminated against because of it, because it is a disability. I thought it would affect my career, destroy my livelihood, affect the way people regarded me. I did not want to be defined by it, or my career limited by it.

‘Since then I have worked very hard indeed to keep my MS hidden, as should be my prerogative. So only a handful of people have known – and Charles wasn’t one of them. I’d been seeing him, romantically, for only two months or three months, and still hadn’t told him. It’s hard, isn’t it, knowing when you reveal something like that. Some people do from the off, but I chose not to. And I stress that it was my choice. Your medical history is the most private thing.’

Dr Cat Jarman met Earl Spencer during an archaeological dig at his ancestral home of Althorp

Two weeks ago Charles, 60, and Cat, 42, opened up about their new relationship to our sister paper The Mail on Sunday, but there is an unexpected twist to the story. How he found out that his partner is living with MS is now the subject of the most extraordinary legal action, which could see Cat pitted against his ex-wife in a courtroom.

He was told, Cat confirms, by his estranged wife Karen, the current Countess Spencer, who was, and still is, living at Althorp, although that 13-year marriage is well and truly over.

‘She found out from someone close to me – someone I don’t want to drag into this,’ explains Cat. ‘But in the course of a conversation about whether I had been having an affair with her husband – which I can categorically say I had not been, we were very much just friends and colleagues until after the marriage had ended – Karen learned that I have MS. It was also confirmed to her that this was not something that was widely known. And yet she then went to Charles and said: “You do know she has MS, don’t you?”.’

Lady Spencer then went on to tell ‘a string of people’, including – according to court documents, and confirmed by Cat today – staff at Althorp, and even the Countess’s personal trainer. Court papers also say that Cat believes she shared the information with teachers at the Countess’s daughter’s private school and at least one of Cat’s TV colleagues. ‘I’m still not entirely sure who else she shared this private and sensitive information with, which is the point of this legal action.’

Cat’s shock at the discovery her MS was widely known about and the subject of local gossip is still palpable.

‘I just felt utterly sick. I went into a panic, particularly over the implications for my career. I understand that she was hurting, but why would you share private medical information like that, without consent, especially when you knew it was private – and secret. It has been the most stressful time, and with MS you are told that it is most important to avoid stress.’

Charles was also shocked, but not dismayed that he hadn’t been told of this by Cat herself. ‘He has been incredible,’ she says. ‘He completely understood why I hadn’t felt able to tell him at that stage. He knows it was a very personal thing.’

This was in May, and over the next five months, Cat set about trying to find out who knew about her MS (‘impossible. You can’t ask people: “Have you heard anything recently about my health?”’) and trying to stop the Countess ‘blabbing’ to anyone else.

Earl Spencer was told about his new partner’s MS, Cat confirms, by his estranged wife Karen

There had never been much communication between the two women even though Cat was a regular visitor to Althorp (‘she wasn’t interested in the archaeological side in the same way Charles was’), but when Charles revealed to his (by then estranged) wife that he and Cat had moved from being friends to lovers, there was complete communication shut-down.

‘I rarely saw her (during the various archaeological digs that went on), but to be honest Althorp is the size of Monaco. It’s not unusual for someone to be living there and not see them,’ Cat says. ‘And I wasn’t actually at Althorp at any point after their separation.’

Cat tells me she resorted to writing to the Countess, via lawyers, ‘asking her to desist from sharing intimate details about my life. And I also asked her for a list of everyone she had told’.

Her pleas, she says, were ignored.

Then, in October, Cat took further legal advice – and (with Earl Spencer’s support, it seems) set about suing the Countess, claiming that the leaking of what has been reported as ‘intimate secrets’ caused her ‘distress, upset and embarrassment’. The court documents make for astonishing reading, given the context. ‘Dr Jarman did not, at any time, provide her consent to the Countess to disclose that information to any third party or intimate anything to that effect,’ they read. ‘This lack of consent should have been obvious to the Countess, given the nature of the private information and the circumstances in which it was imparted.’

The action also involves a claim for damages and a request for an injunction, banning Lady Spencer from telling anyone else, and requiring her to provide details of everyone she told.

A bizarre turn of events, by any standard, but the situation became even more soap opera-like this week when details from publicly available court documents were reported in a red-top newspaper – causing Cat even more distress, and opening the floodgates to speculation about what her ‘intimate secret’ might be.

‘I am told that no newspaper would be able to publish details of private medical information, but with social media, I cannot stop speculation. And I’m now in a position where people are asking what dirt in my background I am trying to keep quiet. It’s horrific.’

After discussions with her sons – she has two teenage boys, and is separated from their father – she has taken the step of speaking out. ‘One of the most difficult things in all this has been the sense of a loss of control of your own life, but given the circumstances maybe it is time to just get this out there. I did chat to one of my sons about it, and he said: “Mum, you must”, because actually, as things have panned out, I am a good example of how you can still go on to have a successful life with MS.’

It remains to be seen what impact her own disclosures will have on the legal action, but she says there is a point of principle at stake here. ‘Medical information should be confidential,’ she repeats. ‘It is unlawful to share it without consent.’

It is understood that Lady Spencer fully intends to defend the claim brought against her.

This debacle pretty much shatters any hope that the Spencer divorce might be amicable, but there was scant hope of that anyway, given that Earl Spencer has already engaged the services of rottweiler divorce lawyer Fiona Shackleton, who, coincidently, represented Prince Charles when he split from Princess Diana.

Lady Spencer has, outwardly, appeared to handle the break-up with great dignity, posting on Instagram about her attempts to move on – with her menagerie. ‘It hasn’t been easy finding a temporary rental that can accommodate seven horses, two sheep, four cats and a dog – but with the help of some wonderful friends, we’ve finally found one,’ she wrote this week. ‘It’s been a most challenging time but also one filled with so much generosity and kindness. No exact move-in date yet, but we’re getting close.’

While Cat says she does not want this to ‘turn into a mud-slinging’ exercise, she does not support the idea that, as the wronged wife in this situation, Lady Spencer should be given some leeway or the benefit of the doubt.

‘It was a long journey before we got to the point of legal action. She had ample opportunity to put this right,’ she says.

It’s also ‘utterly wrong’ that she should be blamed – by Lady Spencer, or anyone else – for the break-up of that marriage.

‘The end of the marriage was categorically not my fault. He did not leave her for me at all. The marriage was most definitely over before anything developed between us.

‘I can understand that she finds it difficult because he moved on before she did, but the narrative that Charles, or I, did something wrong here is simply not true.

‘I do have sympathy for her. I understand what she has lost, because it is more than her marriage and her home. But this still doesn’t justify what she did.’

This is all so terribly sad, because Dr Jarman could be a very positive role model for those coming new to an MS diagnosis.

She says she knew nothing of the disease before it came up as she frantically googled her symptoms back in 2016, while waiting for a raft of scans and tests. ‘Even then I pretty much narrowed it down to the fact that I had a brain tumour, or MS, and what I read about MS seemed so scary that I would have taken the brain tumour’. The diagnosis actually changed her life path. Plan A – to be a ‘serious scientist’, she says – went out the window ‘because to concentrate on research I needed fine motor skills for lab work. If I couldn’t use my hands I wouldn’t be able to do that’. Instead, she pivoted into ‘public engagement and media work. I realised I could communicate this stuff, rather than doing it.’

And this radical career swerve paid off. Dr Jarman, who is Norwegian by birth and studied archaeology at Bristol University, was – and is – hugely successful in her field. Her first book, on the Vikings, was a best-seller, and her TV career took off.

Ironically, it also brought her to Althorp, and – eventually – into the arms of Earl Spencer, for better or worse.

• For more information on MS visit the Multiple Sclerosis Society at mssociety.org.uk