Michael, now Lord, Heseltine launched a Conservative leadership challenge to Margaret Thatcher in 1990, triggering a contest won by John Major, after Lady Thatcher resigned as PM.
He added: "The key point is the (European) Commission has to be prepared to come to that party and say, "yes, we are prepared to show some flexibility on this", so that there can be a UK-wide free trade deal".
In his weekly column in The Daily Telegraph newspaper, Johnson, bookmakers' favourite to succeed Prime Minister Theresa May, called on the government to avoid turning on the "hard-pressed taxpayer" for money to fund public services, and instead embrace Brexit to spur a "dynamic economy".
Pro-Brexit Tories are said to have spent several hours plotting to oust her on Tuesday night because they think she's betraying their vision of a clean break from the EU. An informal summit in Salzburg this month between the EU's 27 remaining leaders is emerging as one of the most significant Brexit discussions since the bloc first set its strategy for talks. The pound has risen in recent days on more positive news of the prospects for reaching a settlement, after falling during the summer over fears that the negotiations are at risk of breaking down.
Hammond said that "if we leave the European Union without a deal. we could expect a period when there would be some turbulence".
Treasury chief Philip Hammond told a House of Lords committee that he agreed with the EU's chief negotiator, Michel Barnier, that a deal was possible in six to eight weeks if both sides are realistic.More news: Justin Bieber and Hailey Baldwin ‘already married’ two months after getting engaged
He also lashed out at the Northern Ireland "backstop" - the measure aimed at making sure there is no hard border with Ireland. People are stuck in entry-level jobs and they're not progressing.
One of the people said the special Brexit summit was being lined up for the week of 12 November.
"Of all the years that I've sat in this chair, this coming year is one of the most hard to give guidance on because there is this uncertainty of the Brexit outcome", Associated British Foods finance director John Bason told Reuters. "We have been involved in far more significant tumult than this".
If a deal has been reached by then, it will need to be approved by MPs. British politicians inside May's governing Tory party, as well as in the opposition Labour Party, are preparing to sabotage the agreement.
He joined Jacob Rees-Mogg and other Tory Brexiteers at the launch of a report by the Economists For Free Trade (EFT) group which claims a hard Brexit would boost United Kingdom revenues by £80billion over 15 years.
The controversial agreement, which set out a blueprint for the future relationship with the European Union following Brexit, has led to the resignation of then-Brexit Secretary David Davis and Johnson. On Wednesday, the ERG will put forward its own plan for resolving the Irish border question.