A vote to leave the European Union would strengthen the case for Scottish independence, William Hague has said.
The former foreign secretary also said a so-called Brexit would “gravely weaken” the UK’s former continental partners.
Stephen Gethins, the SNP’s Europe spokesman, said the intervention read like a desperate begging letter on behalf of a government realising how close it has brought the UK to quitting Brussels.
Writing in The Daily Telegraph, Lord Hague said Scottish nationalists would jump at the chance to re-open the independence debate north of the border if there was a vote to leave the EU in the forthcoming referendum on Britain’s membership.
At the same time, he said, the loss of one of the EU’s only two “respected military powers” would leave the bloc seriously weakened at a time of political turbulence and economic volatility.
“To end up destroying the United Kingdom and gravely weakening the European Union would not be a very clever day’s work. So, even as a long-standing critic of so much of that struggling organisation, I am unlikely in 2016 to vote to leave it,” he wrote.
While he insisted that he remained a Eurosceptic describing the EU as “remote, expensive and over-regulating” he said it was “manifestly not in our interests” for it to fail.
“Scottish nationalists would jump at the chance to reverse the argument of last year’s referendum now it would be them saying they would stay in Europe without us,” the peer added.
“They would have the pretext for their second referendum, and the result of it could well be too close to call.”
North East Fife MP Mr Gethins said the intervention looked an attempt by the Tory leadership to roll back from vain attempts to placate its own backbenchers and Ukip supporters.
He said: “While it is welcome progress to see senior Tories finally ceding that it would be completely unacceptable for Scotland to be dragged out of the European Union against its will we still have no answers as to how they will ensure this does not happen.
“David Cameron’s clumsy handling of EU negotiations are a lesson in how to lose friends and alienate people resembling more something out of a Laurel and Hardy Christmas special rather than any serious strategy to achieve real, lasting and beneficial reform.”