Lord Michael Heseltine has claimed there is no longer a majority for Brexit, as "very large" numbers of elderly leave voters have died since the 2016 referendum.
The former deputy Prime Minister made the comments as Boris Johnson announced he had requested the suspension of Parliament, which could help him push through a no-deal Brexit.
However, Lord Heseltine claimed the move, if approved by the Queen, could result in "the most serious repecussions".
"The referendum was narrow and it has long since ceased to have a mandate. It was based upon a lie about the benefits to the British people, which don't exist," he told talkRADIO's Ian Collins.
"It was based upon a lie about the benefits to the British people which don't exist, and since that time very large numbers of elderly people who were deceived by that have died, and a younger generation has taken over."
Britain voted to leave the European Union by 52 per cent to 48 per cent, but Lord Heseltine said that figure would be different now.
"Of the people who voted to leave, they were very largely elderly people. A large number of which have died in the three years since the referendum and they have been replaced by a large number of young people who voted exactly the opposite."
The peer added: "There is no majority any longer for Brexit as the recent European elections show."
Lord Heseltine claimed the Prime Minister was "frightened of Parliament", which is why he has put the wheels in motion to prorogue it.
"The British people’s power rests in Parliament," he said.