The former deputy prime minister told BBC television's On the Record that the Tory leadership contest was threatening to hand Tony Blair "a priceless card", with the party losing touch with Europe and slamming the door on further integration.
In an appeal for MPs to back Kenneth Clarke in this week's leadership ballots, Mr Heseltine criticised the decision of William Hague and John Redwood to rule out joining a single currency.
He said that would be an unwise challenge to a "significant number" of Tory MPs. "It would have a serious risk of igniting a period of disunity which would be exciting perhaps for everybody, but which would in my mind recreate the atmosphere of 1979, not in the Conservative Party, but in the Labour Party..."
The Heseltine warning was underlined by Lord Rodgers of Quarry Bank, who, as William Rodgers, was one of the gang of four who led Labour MPs into the SDP in 1981.
He told BBC radio's The World this Weekend that what was happening in the Conservative Party today was "so like what happened 20 years ago in the Labour Party".
Nevertheless, last week's traumatic battle was fought all over again on the BBC Television Breakfast with Frost programme yesterday, with Mr Clarke warning of the consequences if Mr Hague and Mr Redwood persisted in locking out membership of a single currency for at least 10 years.
"They're not going to get many pro-Europeans into their Cabinet if that becomes the key element of their appeal," Mr Clarke said.
Nevertheless, Mr Hague - the favourite for the leadership contest - said that the single currency "boil" had to be lanced with a clear-cut line for his shadow cabinet.
But he went further still saying that, if elected, he would try to renegotiate any further tranches of sovereignty that had been handed over to Brussels by a Labour Government.
Mr Heseltine said that whoever wins this week, he does not plan to rejoin the shadow cabinet. It is also possible that other pro-European former cabinet ministers might want to return to the back benches, including Sir George Young, John Gummer and Stephen Dorrell.
But Lord Archer could well be willing to offer his services to a new leader. In the Robert Kennedy Memorial Address at the Oxford Union today, he will urge his party to appoint a chief executive to drive the party to victory in the next general election.