Mr Blunkett was facing renewed questions about a company owned by the family of Tariq Siddiqi, a businessman who introduced him to a 29-year-old estate agent, Sally Anderson. When David Blunkett resigned as Home Secretary last year he briefly took up a non-executive directorship with DNA Bioscience, a company which offers DIY paternity tests and has carried out work for the government. Mr Blunkett was with the company for two weeks before he resigned and returned to the Cabinet as Work and Pensions Secretary.
Yesterday the Tories called for the Parliamentary Commissioner for Standards to launch a probe into Mr Blunkett's involvement with the firm after Ms Anderson, speaking to The Mail on Sunday, claimed Mr Blunkett had told her "he made a number of important introductions for Tariq which had greatly boosted the business".
Chris Grayling, the shadow Leader of the House of Commons, said he was seeking clarification from the Cabinet Office about whether Mr Blunkett had broken the ministerial code.
The firm was placed on a list of 11 government-approved paternity testing centres by the Department for Constitutional Affairs in October 2003.
Ms Anderson alleged in her interview that Mr Blunkett had also left a series of answer phone messages and offered her the use of his flat, in his £3m grace and favour home.
Last night a spokesman for Mr Blunkett insisted he had acted in accordance with the ministerial code "at all times."
"We have already publicly stated Mr Blunkett's involvement with DNA Bioscience. We are not going to comment on false allegations and innuendos," he said. "Mr Blunkett resigned from DNA Bioscience in accordance with the ministerial code when he became Secretary of State for Work and Pensions."