Alex Salmond has urged Tory rebels and Labour to join with the SNP to prevent the in/out referendum on Europe being held in tandem with devolved elections in Scotland, Wales and Northern Ireland.
The former Scottish First Minister, who is now the SNP’s spokesman on foreign affairs, also predicted the Government will be defeated on its plan to lift the prohibition on ministers and civil servants issuing policy statements during election and referendum periods – known as purdah.
Foreign Secretary Philip Hammond has said the Government will “want to make a recommendation on where the national interest lies”, but Mr Salmond said governments should not be permitted to “bias a referendum”.
Mr Salmond told BBC Radio 5 Live’s Pienaar’s Politics programme: “I think there are two issues where the Government faces retreat or defeat this coming week.
“The first, and I think it is quite right for people to be extraordinarily concerned about, is the government attempt to removed the PPERA (Political Parties, Elections and Referendums Act) rules covering purdah and civil service impartiality, basically because the Government drove a coach and horse through them in the Scottish referendum both in terms of their activities and the civil service activities.
“Secondly, this question that David Cameron is clearly angling for to hold the referendum on the same day as the Scottish, Welsh and Northern Irish elections next year.
“Labour and the Conservative rebels will perhaps join the SNP in writing it on the face of the Bill to make it impossible for the Prime Minister to do that.”
He added: “I’m pro-European to my fingerprints but I don’t think Government should try to use the civil service machine during a campaign period – they’re quite entitled to use it within the campaign period of course – to bias a referendum.
“Nor is the Government entitled to break the rules of purdah.
“For example, during the Scottish referendum the vow, the commitment in the final stages of the referendum campaign, was clearly a breach of purdah.
“They had signed up to an agreement that there would be no new political initiatives, and then made one within days to go in the referendum campaign.
“What is that but an example of driving a coach and horse through the rules?”