His comments come as a new poll shows Boris Johnson is on his way to be the next prime minister.
The former deputy prime minister, 86, outlined his support for Bill Newton Dunn in his constituency in Northamptonshire in the Sunday Times.
The Tory grandee wrote: ‘Before our party was infected by the virus of extremism, he was a Conservative MEP in the best traditions of Winston Churchill, Harold Macmillan and, yes, Margaret Thatcher, whose Bruges speech in 1988 made it clear that “our destiny is in Europe”.’
He went on to say that while he would vote with the Tory party in the Lords and stay a member of his local association, he cannot vote for them because of their position on
Michael Heseltine has vowed to vote for the Liberal Democrats in the Euro elections because the Conservative party has been ‘infected by the virus of extremism’
His comments come as a new poll shows Boris Johnson, pictured with his partner Carrie Symonds in Bempton, East Yorkshire, yesterday, is on his way to be the next prime minister
Mr Heseltine added: ‘I cannot, with a clear conscience, vote for my party when it is myopically focused on forcing through the biggest act of economic self-harm ever undertaken by a democratic government.’
On Thursday, Mr Johnson announced he would stand for the Tory leadership when Theresa May steps down and he is the clear favourite, according to a YouGov poll of Conservative Party members for The Times.
The news comes as John Major called for an inclusive Tory party, while Labour MP Margaret Hodge was recorded saying people should vote tactically in the upcoming elections – even if that means not voting for her party.
The former prime minister told The Sunday Times that the need for an inclusive Tory party is ‘greater than ever’, and warned: ‘The middle ground of politics is empty.’
On Thursday, Mr Johnson announced he would stand for the Tory leadership when Theresa May, pictured leaving a church service near her Maidenhead constituency today, steps down and he is the clear favourite, according to a YouGov poll
At an event last week, Ms Hodge was heard saying: ‘I think taking whatever action you need, within your locality, that gives you the best likelihood of electing somebody who will be a pro-European MEP, I think is the way you should go, I really do.’
When asked later about the comments, Dame Margaret told the Sunday Times: ‘I probably misspoke then.
‘I would never advocate voting against the party.’
The Brexit Party are predicted to win the vote next week, with a Comres poll placing them on 31 per cent.
Labour are second on 22 per cent, with Lib Dems third on 16 per cent, and the Green Party and Tories in joint fourth on 9 per cent.
His comments come as Labour MP Margaret Hodge was recorded saying people should vote tactically in the upcoming elections – even if that means not voting for her party.