Nick Clegg said he will not enter another coalition with the Conservatives on the political "platform they set out" at the party's conference last week.
Senior Lib Dems have criticised their current coalition partners over their proposed benefits freeze, with Business Secretary Vince Cable expected to continue attacks on the Tories in his conference speech later today.
The Deputy Prime Minister told Good Morning Britain he did not think his party should enter a coalition "at any cost".
You might have thought that the Lib Dems don't get too cross about anything - but the personal tax threshold has really got them going.
With the support of the party leadership, the Lib Dems may be set to drop their opposition to a new runway at Gatwick airport.
Liberal Democrat leader Nick Clegg has unveiled plans for a string of garden cities along a new railway link from Cambridge.