As Tories accuse her of making 'noises off', what role does Cherie Blair really play?

"Some people find it impossible to believe that she doesn't want to do my job as well as her own... But in fact she doesn't."

"Some people find it impossible to believe that she doesn't want to do my job as well as her own... But in fact she doesn't."

More than six years after Tony Blair first fended off accusations about his wife's political ambitions, the views and role of Cherie Booth QC were yesterday once again firmly in the spotlight.

As the Blairs posed for their annual summer photo-call in Tuscany, back home the controversy swirled over Tory claims that the Prime Minister's wife was indeed the power behind the throne.

John Bercow, the Tory Home Affairs spokesman, made clear that he thought Mr Blair doth protest too much, adding a Shakespearean flourish to a bitter attack on the First Lady of Downing Street. Having declared that Mrs Blair was "an unaccountable cross between Hillary Clinton and Lady Macbeth", Mr Bercow refused to back down from his remarks, despite criticism from some Tories.

To many Labour MPs, the only time Mrs Blair has come close to resembling Lady Macbeth was when she opened the front door to the world's press the day after the general election, her bird's nest hairstyle snapped by all and sundry.

Fraser Kemp, the Labour MP for Hougton and Washington East, claimed the allegation would be laughable if it was notso serious. "The bottom line is they simply don't like the idea of working women. Millions of working women will feel insulted by this attack," he said.

But for the Tories, Mrs Blair's influence over her husband and her tendency to speak out on controversial topics have proved increasingly irritating.

Although it was her defence of the Human Rights Act on Monday that triggered the attack, the party complains that she has offered her opinions on everything from gay rights to élitism in the judiciary.

Mr Bercow's attack was definitely not an off-the-cuff gaffe, having received the full backing of Conservative Central Office and the approval of William Hague. Central Office even compiled a thick dossier that listed Mrs Blair's past comments and her links to Mrs Clinton. "Hillary Clinton was one of the first people to telephone and congratulate Cherie on the birth of Leo," it whispered, wink-wink fashion.

A senior Tory source said: "As a laywer, Cherie Blair is set to make a mint from the Human Rights Act; we have to point that out."

Mr Bercow refused to back down yesterday. "We have experienced regular 'noises off' from Cherie Blair over a period on controversial issues of public policy - parental leave, trade union rights, job share schemes, racial and sexual discrimination and now the highly charged issue of the incorporation of the European Convention on Human Rights into British law," he said.

"These are deeply contentious areas of public policy. By convention, prime ministers' spouses do not intervene in public debate. It would be helpful if she would respect that long-standing convention."

Certainly, Mrs Blair, a distinguished QC and recorder earning more than her husband's £112,000 salary, has little in common with the traditional version of a premier's wife.

She is the first spouse of a Prime Minister to have stood for Parliament in her own right, contesting Thanet in 1983, as well as the first to have a high-flying career. The only connection she shares with Norma Major, not to mention Mary Wilson, was an initial desire not to move into Downing Street with her husband.

True to the traditional pattern of a stay-at-home political wife, Mrs Major's main claim to independence was her interest in opera. Even though he was the first man in the job, Denis Thatcher was as equally subdued, always walking dutifully two steps behind the leader. "She runs the country, I run the family," he said.

The role of PM's wife as a discreet aide on foreign trips was epitomised by the Douglas-Homes. When the former Tory premier made a speech beginning, "I'm very glad to be here in Moscow..." his wife rescued him by hissing: "Peking, Alec, Peking!"

Having been an active member of the Campaign for Nuclear Disarmament, Mrs Blair has always been seen as more left-wing than her husband. In one interview in 1995, she was asked if she read The Sun. "Certainly not. I wouldn't have it in the house," she replied.

But although she may push harder on some topics, such as parental leave, her opinions are remarkably similar to her husband's. Having made a pact with him that only one of them would pursue a political career once elected, she has stuck to it. Instead, her stated ambition is to become a judge. "If one day I was asked to be a judge, I would love to be one," she told Channel 4 News soon after her husband was elected the Labour leader.

Even Mrs Blair's allies admit that it is this goal that could conceivably cause some embarrassment for her husband. The Queen appoints judges on the advice of the Lord Chancellor and appeal court judges on the advice of... the Prime Minister.

Friends of Gordon Brown, the Chancellor, were suggesting yesterday that it was this fact that could even lead to Mr Blair standing down midway through the next parliament, leaving the top job to their own man. Whether the new Mrs Brown would agree with such a plot is another matter.

Last night not all Tories were agreeing with the Bercow line. Ffion Hague, who has her own career, let it be known to friends that she was unhappy with the personal attack on her counterpart.

The Tory backbencher Peter Bottomley said Mrs Blair had a right as a leading QC specialising in employment law to speak out. "It is perfectly reasonable for Cherie Blair to give her view on this sort of subject."

Fiona Buxton, the author of a pamphlet on women for the Conservative think-tank, the Bow Group, was also critical. "There are much more important issues that voters are interested in. I don't think anybody is particularly interested in the political ambitions of Cherie Booth," she told BBC Radio 4's The World at One. "I think she is not a good target."

But in case Mrs Blair gets remotely depressed about the new attention, she would do well to remember that it could have been much worse.

In March this year, she and Mrs Clinton were due to share a platform at a legal conference entitled "Behind every great man - a woman laywer?" Hillary pulled out at the last minute - to concentrate on her fight for the New York Senate.