You've got to hand it to her. Heather Mills just won't go quietly. And despite being vilified in the press, she's still holding her head up high and campaigning fearlessly for the causes she believes in. On the eve of her trip to Oxford for Viva! she tells Katherine MacAlister what it’s been like being Heather Mills over the past few years.

You don’t mess with Heather Mills, especially if you’re a journalist. With endless court cases on the go, get it wrong and she’ll sue.

So I’m just going to say it as it is. As long as you talk about the things she wants to talk about, Heather Mills is very nice.

I can’t vouch for her without her vegan hat on – maybe Sir Paul McCartney can – but she was open, honest and focused when we chatted on the eve of her visit to Oxford to promote her live cookery show for Viva!

Of course there were all manner of things I was forbidden from mentioning; Paul McCartney, The Divorce or her current partner, so I didn’t. I value my job too much.

And yet, whatever you talk to Heather about, her past sits like an enormous elephant in the corner. And I sense Heather understands Nelly is now part and parcel of who she is, like it or lump it.

In the meantime, Heather has put the bad headlines behind her and got on with her life.

What to believe of course is hard with so many lawsuits flying around, but placing her personal life firmly to one side, Heather has been pouring her ferocious energy into her charities and her daughter.

“I’m pretty good with time management,” she tells me. “I drop my daughter off at school in the morning, go for a run or do some exercise, and then work all day until I pick her up, after which that time is ours.

“Then I work again after Beatrice’s in bed. So I work like crazy but when I’m off, I’m off, and you won’t be able to get hold of me unless there’s an emergency,” she says firmly.

Despite her ‘colourful’ life, the 42-year-old has always been a fierce campaigner for Viva! (Vegetarians International Voice for Animals), before and after Sir Paul, but when the divorce proceedings became so acrimonious it was damaging her charity work, she withdrew until the mist cleared, and did what all harassed celebs do – disappeared to the US.

“I was beginning to drag the charities down and harm them because of what was going on in my personal life,” Heather says. “So I stopped and slipped away for a bit because everything I did in England was destroyed and I was doing more harm than good. So I went to the States and spent millions over there helping charities and setting up a café in The Bronx for disadvantaged school children.”

Now back on UK soil, Heather has tentatively been making more public appearances and hoping the ‘hate campaign’ has died a death and she can get on with what she loves best, promoting her charities, which concentrate on veganism, prosthetic limbs and landmines.

“I’ve been dipping my toe in the water with Dancing On Ice,” she says, “and there was such an incredible response that I started doing my Viva! cookery demonstrations again and realised I should have faith in the public. “I’m a campaigner for what’s right – I still have a voice for everyone who can’t speak for themselves, especially animals.

“But yes, I have toughened up. I used to be trusting and honest and said what I thought. But I’m not a bitter and twisted person.”

Nevertheless, the last few years must have taken their toll, because love or hate her, you wouldn’t want to be her. So why does Heather keep coming back for more?

“I think because I nearly died four times, my sister said her goodbyes twice,” she says, presumably referring to the road accident when a police motorbike on a 999 call collided with Heather in Kensington, causing her to have her left leg amputated six inches below the knee in 1993, “and because I’ve worked in war zones. So physical deformities like amputation and losing limbs don’t affect me anything like as much as injustice does.

“Out of principal I fought every case, but they take at least two years each to come to court.

“And it cost them a lot of money. I just hope their lies were worth it. I fought the Press Complaints Commission and the papers. Since then I’ve had so many apologies and they’ve (the tabloids) had to pay their own legal fees and have all backed off now, because they’ve had to pay out a fortune for their lies.”

Now that’s all water under the bridge, Heather is optimistic about the future.

“It’s great. I’ve always been an optimist and seeing people becoming enlightened by veganism and its healthy effects is good news.

“I love to be making a difference. But I’ve also learned to say no. I get thousands of requests a day and I used to say yes to all of them. I was like an octopus. So now I’m concentrating more on the things I do support and have committed myself to.”

This includes a chain of VBites vegan cafés, the first of which has opened in Brighton, near where she lives in East Sussex, and the launch of Redwood – an ethical company which makes the meatless meals sold in Holland and Barrett.

“People were quite sceptical about a café on the beach in Brighton, but it has movies, a creche and cupcakes because we want to show that vegan doesn’t mean food doesn’t taste nice – it’s just healthier and better for the environment without being harmful to animals. And it’s hard to find an overweight vegan,” she laughs. “My mission is to show people that being vegan doesn’t mean you’re a hippy who eats risotto and doesn’t wash, but can be sexy, funky and healthy. Because when people fear something they criticise it...”

Perhaps the same applies to her? “I have great friends and family in my life. And I have a healthy and lovely daughter. You just have to get on with it,” she says. “I’ve been doing the cookery shows for years and when I do them they triple in size. So while we do hail from an unfortunate celebrity era, getting the message across rather than appearing on Big Brother seems as good a reason as any. But I don’t think I’ll convert the carnivores overnight. I’ll take things one day at a time,” and with that she’s gone, elephant and all.

Heather Mills’ Incredible Veggie Cookery Show comes to Oxford’s King's Centre in Osney Mead next Thursday, June 10. Call 0117 9441000 for ticket information.