Nick Clegg has fuelled speculation that he is positioning for coalition with Labour next year by saying he believes Ed Miliband's party has "changed".
The Deputy Prime Minister also criticised the Tories for lurching to the right, accusing his current partners in government of becoming "much more ideological" since 2010.
The comments, in a BBC Radio 4 documentary, follow an apparent thaw in relations with shadow chancellor Ed Balls.
More top news
A mother has been arrested on suspicion of attempted murder after her three young children were found with their throats cut.
Ex-Cuban leader Fidel Castro has broken his silence over Cuba and the United States' attempts to repair diplomatic relations.
David Cameron has pledged to reduce the annual benefits cap to £23,000 "within the first few days" of a Conservative election win.