Those disappointed when Tony Blair had to cancel a book-signing due to protests last month will be pleased to learn they can now buy the former prime minister's signature – from his wife, Cherie.

Cherie Blair, a barrister who together with her husband has amassed a large fortune, sold a signed "bookplate" on eBay for £10, it has emerged.

The enterprising former Downing Street resident offered the item – designed to fit into copies of Tony Blair's autobiography A Journey – at £25 on the auction site last week.

However, Cherie, whose love was famously "devoured" by her husband on the night he decided to run for the Labour party leadership, found that the bookplate was less eagerly snapped up.

Blair does not use her full name on her eBay account, but Paul Hurworth, 35, from Pickering, North Yorkshire, uncovered her identity when he sold a silver butter knife and glass dish to her account, and records showed it was registered to the family's main London home.

"It [Tony Blair's signature] was reduced to £20, then finally a tenner," Hurworth told the Evening Standard.

"Why would she keep reducing the price if she wasn't trying to sell it?

"No matter how you look at it, it's an embarrassing thing to do for a tenner when you're worth millions."

Cherie has denied the auction took place as a mere money-making scheme, her spokesman explaining that it was a philanthropic gesture.

"Cherie Blair was cross that people were selling Tony Blair's signature when you can get one free," the spokesman said.

"She was trying to undermine the market and as soon as someone bought it, she refunded it straight away to make the point."

In September, Tony Blair pulled out of a planned book-signing in London because of security fears. Unrest at his Dublin signing saw the former prime minister pelted with eggs and shoes.