A ministerial aide tells us he is now abstaining tonight on the vote (he could have a free vote).
He thinks No 10 has done enough with its draft legislation.
Cameron has pledged to back a Conservative MP's EU referendum bill, as Cable labelled the move potentially 'damaging' for the country.
114 Conservative backbenchers have voted in favour of a eurosceptic motion to amend the Queen's Speech in defiance of the Prime Minister.
David Cameron has denied he has buckled under pressure from his backbench MPs over the EU debate.