The offer was revealed by a leaked letter from a Conservative supporter to fellow-businessmen who were invited to a fund-raising lunch last week.
The Labour Party said it blew apart Conservative claims that there was no link between financial support for the Tories and influence over government policy. John Prescott, Labour's deputy leader, said the Conservatives had created "a corrupt system of government for hire".
The letter, from Robert Ogden, a Tory supporter and wealthy racehorse owner, invited businessmen to lunch last Friday at his home, Sickling Hall in North Yorkshire. The Cabinet guest was Stephen Dorrell, Secretary of State for Health.
In his letter, Mr Ogden said he was writing "about the impending general election". He wrote: "Following a recent request from The Rt Hon Dr Brian Mawhinney MP, chairman of the Conservative party, I am organising support for the future campaign and my intention in approaching you is to find out whether you would be prepared to help."
The lunches and dinners at his home, he wrote, would be "an occasion for prominent businessmen in our area to discuss the conduct of the campaign and to enlist their financial support".
Then he added: "There will be plenty of opportunity for you to air your views on current issues and to suggest a strategy for dealing with them in the months leading to the general election. You can be confident that your advice will be listened to at the highest level in government."
Mr Prescott said he would write to John Major to find out what rules or guidelines govern discussions on government policy when ministers take part in fund-raising occasions. He said: "This is proof beyond all question that influence over the Government is on sale in return for donations to the Tory party.
"No wonder John Major has blocked Labour's demand for an inquiry into party funding by the Nolan Commission".
Conservative Central Office refused to confirm that Mr Ogden had Dr Mawhinney's backing for his letter, saying it "never talks about Conservative party finances". But it accused Mr Prescott of making "idiotic statements in the week that the Labour Party have hired a professional fund-raiser to try to tap-up business for Tony Blair".
A spokesman for Mr Dorrell rejected the notion of any impropriety. He said: "All arguments are listened to at the highest level in government. Ministers meet businessmen every day. That includes people who give money to the Conservative party and people who do not. They are all listened to equally. How many members of the Shadow Cabinet this weekend are not attending some meeting sponsored by a union?"
The Conservatives give only the vaguest details about the sources of donations, which are thought to include many overseas businessmen, while Labour declares its funding from unions. However, many companies have cut their contributions to the Tory party in recent years.Reuse content