First Lady for hire: Cherie joins Clinton, Major and Bono on the lucrative US speaking circuit

Despite earning £125,000 a year as one of Britain's leading human rights lawyers, Cherie Blair has a reputation for thrift: witness her partiality to second-hand shoes touted on the eBay website.

But the Prime Minister's wife may soon feel that she can get away with a little more extravagance. She has just been signed up by the Harry Walker Agency, one of the glitziest celebrity bookers in New York. Their job is to find clients to hire Mrs Blair for speaking engagements, a sideline that could propel her earnings into the stratosphere. Those already on the agency's books include Bono of U2, Henry Kissinger and Bill Clinton, who can command fees of £160,000 a time for public engagements.

Baroness Thatcher and John Major - whose speaking style was ridiculed on Spitting Image - both earned small fortunes on speaking tours in the US. A leaked e-mail from the agency said Mrs Blair was available for suitable speaking engagements, providing the price was right, on 26, 27 and 29 October, with a "value for money" guarantee.

The e-mail was sent to potential clients on both sides of the Atlantic by one of the chiefs at the agency. It read: "I have exciting news. Cherie Blair, noted British attorney, human rights advocate and the wife of Prime Minister Tony Blair, has agreed to speak under our auspices this fall for a limited number of engagements.''

"Prime Minister Tony Blair", the e-mail added, says his wife "is an enormous source of strength and an extraordinary person in her own right. I never know how she manages with all the different things she does - the work, the family."

The e-mail continued: "I know Cherie Blair would be a great success at your next event, so please contact me today for more information about her lecture topics, October schedule and future scheduling opportunities."

Mrs Blair's Matrix chambers said: "She is already speaking in the US in October, which has been in her diary for some time, and she has accepted an invitation from this agency to speak while she is in the US on subjects which are within her professional expertise."

The subjects could be wide ranging because Mrs Blair, who practices as a QC under her maiden name, Cherie Booth, is an expert on employment law, education law, public law, human rights and EU trade law. She met her husband in the same practice when the former Lord Chancellor, Lord Irvine, was the head of chambers.

She was called to the Bar in 1976 after being educated at the London School of Economics, and became a recorder in 1999, sitting part-time in the county court and Crown court. As a taster of what the US can expect, at the Reform Synagogues of Great Britain seminar on human rights and Judaism in February, she spoke warmly of H G Wells and the influence he had on Franklin D Roosevelt.

And in an echo of her husband's speeches, she said: "With human rights there are also duties or responsibilities. In today's world we commonly hear when an individual is being denied their rights, but less so about when it comes to discharging their duties. Society can only function because most of us understand that bargain."

She hit the headlines with a speech on children's rights for the charity Barnado's. But her most famous speech was her highly emotional and unprecedented public apology in 2002 over the "Cheriegate'' affair. She apologised for her relationship with the convicted fraudster Peter Foster, then boyfriend of her lifestyle adviser, Carole Caplin, and over the purchase of two flats in Bristol.

"It is not fair to Tony, or the Government, that the entire focus of political debate at the moment is about me," she said. "I know I am in a special position. I am the wife of the Prime Minister, I have an interesting job and a wonderful family, but I also know I am not Superwoman. The reality of my daily life is that I am juggling a lot of balls in the air."

Her US agency is not saying how much she will earn on her tour. But it raises interesting questions over how long will it before her husband joins Mrs Blair on the lecture circuit. They sold their house in Islington for a reputed half-a-million pounds before they moved to Downing Street. They are both capable of becoming millionaires when the lure of No 10 begins to pall.

Today Mr Blair is at the Olympics in Athens before the Blairs continue their family holiday in Italy as the guests of Silvio Berlusconi, the Italian premier and billionaire media tycoon. It is a lifestyle Mrs Blair may soon be able to afford.

SPEAKERS' CORNER

* Former US president Bill Clinton earns between £60,000 and £160,000 per speaking engagement. He receives about 100 requests a week to speak. He was reported to have recently turned down £160,000 to appear at an Italian music festival

* Margaret Thatcher earned £30,000 an appearance for public speaking, but was warned by doctors in 2002 to stop after a minor stroke

* Sally Gunnell, the former athlete who is now a sports commentator, also performs as a motivational speaker for as much as £10,000 a time. She speaks 40 to 50 times a year, including at conferences for big firms such as IBM and Ernst & Young

* Joanna Lumley is one of the highest-earning women on the speaking circuit. The actress earns up to £25,000 a speech with lines such as: "Men don't like to be led by women. They don't mind being spanked by them, but they don't like to be led by them"

* The former footballer Gary Lineker charges £25,000 a time, but only gives 10 to 12 speeches a year because of his commentating schedule with the BBC