Boris Johnson chose to play with fire over Brexit and now the British people risk being burned

“It is surely a boon for the world and for Europe that she [Britain] should be intimately engaged in the EU. This is a market on our doorstep, ready for further exploitation by British firms: the membership fee seems rather small for all that access.”

So, remarkably, wrote Boris Johnson, just two days before coming out for Leave. He penned the unpublished article, revealed in a book by the political journalist Tim Shipman, as he weighed up the arguments for leaving or remaining in the EU before announcing his decision to the waiting world.

There is no doubt that Johnson’s verdict mattered. Arguably, it changed the course of British history. Even Nigel Farage has admitted that the Leave camp would probably not have won the referendum without Boris, who gave it the X factor appeal it would otherwise have lacked.

Johnson’s draft article admitted that Brexit could hasten the break-up of the United Kingdom by persuading Scotland to leave. His warning now looks prophetic, as Nicola Sturgeon prepares to publish a bill for a second independence referendum, to be held if Scotland cannot remain in the single European market, as she continues her game of chicken with Theresa May.

Although friends describe Johnson’s unpublished piece as half-hearted, it could be seen as part of a genuine attempt to look at both sides of the argument as he faced an agonising dilemma.

These friends insist that he was warned by Ben Wallace, a close ally, that coming out for Leave would damage rather than enhance his prospects of succeeding David Cameron. Yet the episode reinforces the impression of a man taking a decision out of self-interest rather than the national interest. Wallace also told Johnson: “The upside is that if the ‘outers’ win, then you will be masters of all.” It didn’t quite work out like that; a Remainer became Prime Minister, although the job of Foreign Secretary was a pretty good consolation prize

All the signs are that Johnson did not expect Leave to win the referendum – including that look of utter shock on his face on the morning after, and the Leavers’ total lack of a plan for Brexit. (We still don’t have one now, almost four months after the referendum).

Johnson’s decision looks like an each-way bet: if Remain won, he would build up his credentials with Tory Eurosceptics, boosting his prospects of succeeding Cameron when he stood down before the next general election. If Leave won, then Johnson would have a very good chance of entering Downing Street quickly. Cameron always believed privately that “Boris will do what is right for Boris”. On that, he was proved right.

Johnson now claims that when he wrote the article, it was “blindingly obvious” that the right thing to do was to back Leave. However, other accounts suggest he was in turmoil until the last minute. According to a book by Sir Craig Oliver, Number 10’s former director of communications, Johnson had a characteristic “wobble” after informing Cameron he would back Leave. “Depression is setting in,” he told Cameron in a text message.

Cameron described Johnson as a “confused Inner”. That fits with the impression that Johnson believed a referendum decision to leave would force the EU to make further concessions to Britain to keep it in the club. The improved deal could then be put to the British people in a second referendum. If Johnson did believe that, it was a misjudgement; it is not going to happen.

If Johnson was not sure about such a momentous decision, surely he should have backed the status quo rather than risked Brexit. Instead, he decided to play with fire and it is the British people who now risk being burned.

The least the Foreign Secretary can do is to be true to his own words in the unpublished article and argue inside the Cabinet for the closest possible links to the “market on our doorstep”. Let us hope that he now puts the national interest first.