The future of the UK would be imperilled if Scottish nationalists prop up a Labour government after May 7’s election because they would use the role to prepare another independence vote, former prime minister John Major said yesterday.

Speaking in Solihull, central England, former Conservative leader Major described such an arrangement as “a recipe for mayhem” that threatened the integrity of the UK.

“Let me not mince my words,” said Major. “The SNP is a real and present danger to our future. They will pit Scotland against England. That could be disastrous to the people of Scotland − and fatal to the UK as a whole.”

Scots voted by 55 to 45 per cent to remain part of the UK in a referendum last September, but the Scottish National Party (SNP) has since enjoyed a spectacular renaissance.

Polls suggest it will sweep nearly all Scotland’s seats in the Westminster parliament, largely at the expense of the main opposition Labour Party, becoming the third-largest party overall after next month’s election.

Espousing left-wing policies, the SNP has said it will help Labour lock Conservative Prime Minister David Cameron out of power in return for concessions such as higher public spending. Centre-left Labour has ruled out a formal coalition with the SNP, but left the door open to a looser pact.

The warning by Major, who Britons remember for his understated style and centrist political stance, was the starkest yet by any Conservative on the nationalist threat.

His party is struggling to establish a lead in opinion polls less than three weeks before an election that no single party is on track to win outright.

Nicola Sturgeon, the SNP’s leader, reacted angrily to Major’s intervention, saying it was a sign of the growing desperation of the Conservatives.

Cameron’s party had been banking on a steady economic recovery to hand it victory but opinion polls have put the two main parties neck-and-neck for months and the Conservatives have been criticised for the negative tone of their campaign.

Using Major to send a message directed at English voters in particular is an attempt to broaden the party’s appeal.

Labour portrays Cameron, who enjoyed a privileged upbringing, as the leader of a party of the rich, whereas Major’s roots are far humbler. He was also the last Conservative leader to win an overall majority at Westminster, in 1992.

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.