David Cameron has been defeated in the House of Commons for the first time as a majority Conservative Prime Minister, losing a vote on the purdah rules for the EU referendum 312 to 285, majority 27.

Labour, SNP and anti-EU Tories had threatened to combine to force the Government to change the rules covering next year’s proposed referendum on Britain’s EU membership.

The dispute is over whether the Government should be tied during the run-up to the referendum by rules similar to those applying before general elections, which bar ministers from using the civil service machinery to make any pronouncements that might influence the way people vote.

Under pressure from anti-EU Tories, the Prime Minister has already conceded that there will have to be “purdah” rules before the EU referendum, but the various sides were embroiled in a complicated argument on how those rules should apply.