The Deputy Prime Minister Nick Clegg, is today to warn David Cameron and the Conservative party that it must “get back to governing”, and stop infighting over equal marriage, and the EU.

The Marriage (same sex couples) Bill passed its third reading in the House of Commons tonight, but has caused friction within the Coalition Government, including MPs opposed to the measure tabling amendments which failed, but which could have potentially “wrecked” the bill.

MPs voted 366 to 161 overwhelmingly in favour of passing the bill, giving it a majority of 205. It will now travel to the House of Lords for further scrutiny, debate and voting.

In a speech this morning, Mr Clegg will address the issue of equal marriage, and will also talk down speculation that the Liberal Democrats will separate from the Tories in 2014, in order to set out separate election agendas.

He will say:  “One minute, a Government publishing its third Queen’s Speech: fundamentally reforming pensions; tackling long-standing problems with social care; getting to grips with immigration.

“The next? Westminster consumed by game-playing over Europe and gay marriage; MPs disappearing into a parliamentary rabbit warren, obsessing over this new tactic or that new trick: paving legislation, enabling referendums, wrecking amendments…

“Anyone watching would be forgiven for asking: what are these politicians doing?

“So it’s time to get back to governing; providing the leadership and focus the people of Britain deserve in these difficult times.”

He is to warn against “destabilising the nation”, if the Liberal Democrats “duck out early” from the Coalition government in 2014, in the “vague hope of short-term political gain”.

Mr Clegg, the MP for Sheffield Hallam, will say that it is “nonsense” to think separating from the Conservatives might “suddenly win back” those people “who have never liked us going into government”, with them.

“I am absolutely committed to this Coalition lasting until 2015 – as is the Prime Minister,” he will continue.