Lord Sainsbury resigns after eight years as Science minister

Labour's biggest financial backer, Lord Sainsbury of Turville, has resigned as Science minister after eight years in the job, saying he wanted to devote more time to his business and charity work.

The billionaire peer, a close ally of Tony Blair, was one of 48 people questioned by police investigating the allegations. But he insisted yesterday that his decision to leave the Government had nothing to do with the inquiry. Lord Sainsbury, whose huge private fortune comes from the supermarket chain that bears his family name, has given more than £10m to the Labour Party since 1999. He told the BBC : "I have had a peerage for eight or nine years, so there is no question of buying a peerage."

He suffered an embarrassment this year when it emerged that he had failed to declare a £2m pre-election loan to Labour, but escaped censure after he explained he had confused the loan with a gift for the same amount he had made around the same time. He was awarded a seat in the House of Lords by Mr Blair in 1997, and appointed Science minister in July 1998, which means he has served in the same job for longer than any other minister apart from Mr Blair and Gordon Brown, the Chancellor. He has never drawn a government salary.

His departure caused a shuffle of responsibilities among ministers at the Department of Trade and Industry. The former energy minister Malcolm Wicks will replace Lord Sainsbury, while the Trade Secretary, Alistair Darling, will take personal responsibility for energy policy, including the question of whether there should be a new generation of nuclear power stations.

Lord Sainsbury said: "I've done eight years in the job. I've achieved most of what I can achieve, and I think now is the time really to get back to all my other business and charitable activities, which I've not been able to do during the past eight years." The Chancellor, Gordon Brown, denied Lord Sainsbury was "leaving a sinking ship". He told the BBC the peer had "always made it clear he would leave after a certain time". He added: "He wanted to get back to his charitable work in particular."

As a minister, Lord Sainsbury was one of the biggest government champions of genetically modified foods, but was not able to win over the British public. Mr Blair said that he "worked tirelessly to push the case for science within government".