British MPs on Monday faced an embarrassing defeat of Prime Minister David Cameron as Eurosceptic members of his conservatives united with opposition and voted against suggested ways of holding a referendum on the European Union.

The defeat in the Lower House concerns technical issues but illustrates Cameron's struggle to block Eurosceptics in its own party before voting at the end of 2017. years.

It is the first defeat of the head of government in the Lower House where it has the majority of 16 seats, after winning the May elections. The government wanted to alleviate the usual rules known as "purdah", and these regulations prohibit ministers from making statements in the electoral campaign that could change the outcome of 28's vote in the last days of a campaign or referendum.

The government's will was opposed to 312 votes versus 285. Thirty-seven conservative deputies opposed Cameron.

The prime minister has announced that he will conduct a campaign to stay Britain in the EU, but only if he succeeds in achieving important reforms with Brussels, including the change of the Union's underlying treaties. For example, it is about social assistance to immigrants from the EU.

At a vote on Monday, Eurosceptics have teamed up with the Labor Party and nationalists of the Scottish National Party.