Cameron faces rebellion on referendum rules

Amendments tabled by Conservative rebels would ensure that the government cannot publish pro-European reports on the eve of the vote, nor hold the in/out referendum on the same day as other elections.

Although the government’s referendum bill guarantees a vote by 2017, Cameron is keen to hold a vote next year, possibly to coincide with elections to the Scottish and Welsh parliaments next May.

The rebels say the referendum should be preceded by a 28-day “purdah” period during which the government machine would remain neutral - with ministers and the civil service forbidden from issuing political statements for the last four weeks before polling day. Introduced by the last Labour government, the ‘purdah’ principle applies to all national UK elections.

“If the whole thing is skewed right up to polling day it won’t be seen to be fair,” former cabinet minister Owen Paterson, who is leading the Conservative rebels, said during a BBC interview on Sunday.

Labour has not decided how it will vote on the amendments, although former Scottish National party leader Alex Salmond hinted that his party would support them.

“I’m pro-European to my fingerprints but I don’t think government should try to use the civil service machine during a campaign, ” Salmond told the BBC in a separate interview on Sunday.

However, speaking in the House of Commons last week, Foreign Secretary, Philip Hammond, told MPs that the restriction would be “unworkable and inappropriate”.

Conservative eurosceptics also want to have strict rules on campaign funding for the ‘Yes’ and ‘No’ campaigns, fearing that the pro-EU campaign would easily outspend its rival.

Last week Cameron was forced to back down after appearing to suggest that ministers wishing to campaign for a ‘No’ vote would have to resign from his government,

A number of Conservative ministers are hostile to EU membership and want Cameron to allow a free vote, repeating the tactic used by Labour premier Harold Wilson at the UK’s last referendum on the then EEC in 1975 of temporarily freeing ministers from the principle of ‘collective responsibility’.

Meanwhile, the Conservatives for Britain group, which launched last week and is likely to form the nucleus of the party’s ‘No’ campaign, claims to have the support of over 100 Conservative MPs, including several cabinet ministers.