Ed Miliband will use a speech to indicate that he is ready to work with Liberal Democrats both before and after the next general election.
Writing in The Guardian, the Labour leader held out an olive branch to Lib Dems who are uneasy about their party’s coalition with Conservatives, saying he wants “to co-operate with them in Parliament and outside it” to fight against the direction in which the Government is taking Britain.
Speaking to the Fabian Society later, he will insist he does not intend to “gloat” over the “tragic mistake” made by the Liberal Democrats under Nick Clegg’s leadership.
He will make clear he looks forward to warmer relations with the third party in future, saying that he hopes that Liberal Democrats will eventually come to realise they blundered by agreeing to join a Tory-led Government.
And he will accept that Labour needs to change and “rebuild ourselves as a broad movement of the British mainstream”, after 13 yeas in power in which the party “lost our way”.
“Forgive me if I decline to join those of you who are gloating at the expense of the Liberal Democrats,” Mr Miliband will say.
“Their decision to join a Conservative-led Government was a tragic mistake, and I hope they come to see that in time.”
In his Guardian article, Mr Miliband paid tribute to the influence on Labour of Liberal thinkers like William Beveridge and John Maynard Keynes.
And he said: “Many Lib Dems already see Labour as the main progressive hope in British politics. But there are others who have decided to stay and fight for the soul of their party.
“I respect their choice and understand how painful it must be to watch what is happening. We do not doubt that they hold sincere views and we want to co-operate with them in Parliament and outside it to fight against the direction in which this Conservative-led Government is taking our country.”