A Labour spokesman said the claim in yesterday's Independent was "very serious indeed", and urged the Conservative leader, William Hague, to "clear the air by following Labour's lead in naming those who made significant donations while his party was in office".
The Virgin tycoon said he was approached by a Conservative fund-raiser, and that hints were regularly dropped that he would get "favours" if he made a donation.
Mr Branson says he had received a "bizarre" invitation to dine with a senior Tory he took to be John Major, while he was prime minister, "in the final run-up to the decision" on who should control the Lottery.
It was never as "clear-cut" as explicitly offering a knighthood or another honour, he said. "Everything was done by innuendo. It was made clear that if I scratched their back, they would scratch mine."
Mr Branson refused to name the fund-raiser.
A Tory spokesman said: "The Conservative Party never accepts donations with strings attached, and has never done so. He denied fund-raisers held out the prospect of honours."
Lord Harris of Peckham, the carpet millionaire, who was a leading Tory fund-raiser for more than four years, denied he had been involved in trying to persuade Mr Branson to donate. Having been a Virgin board member in the 80s, he knew that Mr Branson would not donate to any political party. "He had made that quite clear, so I knew it would have been a waste of time approaching him," Lord Harris said.
An assistant to Lord Hambro, another former Conservative Party treasurer, said he never commented to the press.
A spokeswoman for Lord Archer, a leading Tory fundraiser, said he was not commenting on the Branson allegations.Reuse content