London, September 7

Prime Minister David Cameron faces a rebellion from many of his Eurosceptic lawmakers today when Parliament votes on the rules for a planned referendum on Britain’s EU membership.

Cameron has already been forced to make concessions over the referendum, last week agreeing to make the wording of the question more neutral and to accept some limits to government activity in the run up to the vote, which is due by 2017-end.

But many Eurosceptic Conservatives argue this did not go far enough and that a so-called “purdah” period, which bars the government from publishing anything which could influence the outcome, must be applied in full.

The Labour Party and Scottish nationalists have also tabled amendments to the EU Referendum Bill, which lawmakers in the lower house will have their final chance to vote on later today, also arguing purdah must be applied.

As Cameron has a working majority of just 16 in Parliament, the government faces an embarrassing defeat if enough of its own MPs join forces with the opposition parties, forcing it to re-think its plans to accommodate the Eurosceptics’ demands.