Refusing to sanction a fresh poll – even if the SNP triumphs in Holyrood elections next year – is likely to “help the separatist case” by fuelling anger, the former prime minister warned.
Instead, he called for two referendums, the first on the principle of independence, but with a second ‘yes’ vote – on the outcome of the negotiations – required for Scotland to leave the Union.
Sir John suggested it was the way to defeat nationalism, saying: “Scottish electors would know what they were voting for, and be able to compare it to what they now have.
“This did not happen with Brexit: had it done so, there may have been no Brexit.”
The recommendation is made in a lecture in which the Tory elder statesman delivered his fiercest attack yet on EU withdrawal – warning it would be “even more brutal than anyone expected”.
Sir John listed the consequences ahead, including higher food prices, more expensive holidays, more costly health insurance, the loss of the pet passport scheme, higher roaming charges, airport delays and the loss of the automatic right to work, live or study in the EU.
“Small irritations, some may say, but – collectively – a significant loss of freedom that will be an unwelcome surprise to many as Europe itself begins to ‘take back control’,” he told leading lawyers at the Middle Temple society.
Sir John said: “Brexit was sold to our electors on false premises. Promises made will not – indeed, cannot – be kept.
“It defies logic that intelligent men and women making such extravagant promises did not know they were undeliverable – and yet they continued to make them. It was politics. It was campaigning. It was for a cause. It was also unforgiveable.”
And he added: “It now seems that on 1 January next year, Brexit may be even more brutal than anyone expected.”
In Scotland, the ‘yes’ campaign is solidifying its lead as women swing behind independence, wiping out the “gender gap” that had previously shown greater support among men.
Mr Johnson is expected to refuse so-called ‘Indyref2’, even if Nicola Sturgeon’s party triumphs in next May’s elections to the Holyrood parliament and claims a mandate.
But Sir John said: “The Westminster government could agree for an independence referendum to take place, on the basis of two referenda. The first to vote upon the principle of negotiations, and the second upon the outcome of them.”
He added: “Many Scottish voices – and especially business – may support the logic of this: it may focus minds away from a short-term reflex opposition to a perceived English government, and back to the mutual and long-term virtues of the Union.”
