Cherie’s intense eye-contact and open demeanour falter only at the mention of Sarah Brown. Did she give her successor advice? Cherie pauses to pour herself water. “I didn’t specifically give her any advice. We left her some things [champagne and presents for the Brown children] and exchanged some letters . . . But in the end you have just got to do what is right for you.”

Do you think Sarah is doing well? “I think she’s doing brilliantly, don’t you?” she says, rather tightly. “I wish I could have avoided the spotlight as she has managed. And I hope that she doesn’t have to enter it and face the criticism I did.” Indeed, she says that Mrs Brown has benefited from her efforts. “Sarah, I’m so pleased, because that is one of the things I wanted, has more support. She has four people working for her, whilst I had two.”

But is it not true that you don’t get on, in fact haven’t spoken a word for years? “That’s not true. To be honest, the extraordinary thing is we didn’t really socialise and she only married Gordon at a time when we were already in No 10 and there isn’t much time for us to see our old friends or even new ones. So they did their thing and we did our thing. I think she’s doing a fantastic job and she has two small children and I hear she has a book coming out.”

Having met Cherie and, knowing Sarah Brown a little, it is hard to see how these very different women could ever be friends. Cherie’s warm gush and touchy-feeliness contrasts so markedly with Sarah’s cool, ironic, measured reserve. Neither would Mrs Brown, a steely and self-confident businesswoman, for all her recent feminine modesty and silence, be likely to defer to Mrs Blair as junior political wife.

The truth about Tony and Gordon

Cherie Blair reveals her husband is advising Gordon Brown but says he did not trust him enough to stand down early

• 'The problem with me and Gordon is nothing personal'

• Cherie Blair: motherhood, makeovers and making ends meet – my life in Downing Street

• Cherie Blair: the secrecy and sadness behind a remarkable memoir

Multimedia

• Full coverage: Cherie Blair autobiography

BACKGROUND

• My complex life in Downing Street

• Secrecy and sadness behind memoir

• Leo: my miracle baby at 45 (and yes, he did have the MMR jab)

• The night I hated Tony

BACKGROUND

• Miscarriage: ‘I'm afraid the baby's dead, Mrs Blair'

• The Queen and I: relations with the royals

• Cherie Blair's face-off with Campbell over Caplin

• Peter Foster and the ‘scandal' that never was

I bet Cherie is glad she wasn’t in No 10 during the Labour Party’s recent electoral horrors? “But I was there in 2004 when it was announced these were the worst local election results ever and what happened? We won the 2005 election.”

But Tony Blair’s personal popularity never sank this low. “I can’t even remember. This is what happens in politics. It is all up and down.” But isn’t a small part of you pleased that after Gordon badgered Tony for so long to leave, he is finding the job more difficult than he expected? “No, because I have been a Labour Party person since I was 16, and even before that, and I know they are the best party for the country and I want to see them win again. I would be delighted to campaign for them.

“The problem between Gordon and me is not anything personal. It is because I thought my husband was the best person for the job and it is a damn difficult job. As far as Gordon’s impatience about [Tony] moving on was a difficulty, I thought it was a difficulty Tony could do without.

“So I was just terribly partisan for Tony and I’m sure Sarah is partisan for Gordon, and so she should be. And the good thing is Gordon is not alone in No 10. He has Sarah and has the children, so even in these darkest moments he knows there is something important outside politics for him.”

Is it true, as Lord Levy, a former Blair adviser, says in his memoirs, that Mr Blair does not think that Mr Brown can beat David Cameron? “Well, Lord Levy doesn’t know anything! I know that Tony thinks Gordon could win the election and I know that he has spoken to Gordon about how he could do that. Tony has given Gordon advice. He and Gordon talk to each other even now. But I don’t know how often they speak since Tony is abroad so much of the time.”

Times Recommends

• Shrinking violet Gordon turns into raging bull
• Eddie Izzard: 'I keep thinking if I do all these things she'll come back'
• Is sex for the disabled the last taboo?