If Boris Johnson is trying to sabotage his chances of succeeding David Cameron as Conservative Party leader and Britain’s prime minister, he should keep doing what he’s doing.

The outgoing mayor of London took a risk when he joined the campaign for Britain to leave the European Union earlier this year, but that should not in itself have undermined his ambitions. He is likely to end up on the losing side but could have justified his holiday from the political mainstream as an idealistic, if quixotic, indulgence.

The way he has conducted himself since reveals Johnson to be something of an anti-EU fanatic, however, and that could very well ruin his career.

Perspective

When it was reported this week that net immigration from other European countries has been higher than previously thought, Johnson lashed out at his pro-EU counterparts, accusing them of “dishonesty”.

“Politicians, if they’re going to have a pro-migration policy, should take responsibility for it, stand up and explain why they want hundreds of thousands as opposed to tens of thousands,” he said.

The reality is that many in Johnson’s party do not want such high immigration either. But they accept it as the price of EU membership.

Johnson’s inability to see immigration in perspective is not unique. Many Euroskeptics obsess about it. But they are in the minority. Most voters are far more concerned about their jobs, about access to health care, about quality education for their children. That is why the “remain” side is framing EU membership as a boon to the economy and leaving as a threat to businesses and growth.

Hysterics

Johnson would argue the opposite: that it is the EU that is holding the British economy back and that leaving would enable the island nation to make better trading deals with economies in Asia and the United States. No matter that American president Barack Obama and every other foreign leader has advised against an exit and urged Britain to stay in the EU.

Such sensible advice tends to send the outers into hysterics.

In a speech earlier this week, Johnson accused those who claim the United Kingdom is safer in the EU — including former American cabinet secretaries and the former heads of Britain’s intelligence services — of scaremongering, as if “there will be a return to slaughter on Flanders fields” if Britain leaves, he said.

He could (and probably should) have left it at that. But Johnson went one step further, arguing that it was the EU itself, “and its anti-democratic tendencies, that are now a force for instability and alienation.” The bloc’s “pretensions to running a defense policy,” he said — which exist only in his imagination — “have caused real trouble. Look at what has happened in Ukraine.”

Strong stuff for someone who, up to three months ago, did not once in the hundreds of articles he wrote and speeches he gave about the EU advocated leaving.

Former foreign secretary Jack Straw responded, saying, “Boris Johnson has plumbed new depths today by joining the likes of Farage, Le Pen and Wilders in blaming the EU, rather than Vladimir Putin, for what has happened in Ukraine.”

Tantrum

If Johnson’s preoccupation with immigrants, his disregard for world opinion, his cozying up to the Russian dictator and blaming the victim weren’t disqualifying enough, his curious view of negotiation should be.

He recently told The Spectator, a right-wing magazine he once edited, that Britain could have got a better deal in Europe if only Cameron had had the nerve to “swivel the guns of the Dreadnought” on Brussels.

I would have gone [to them] and said: This is what we want, give it to us or the baby gets it.

Which is the equivalent of a child throwing a tantrum if it doesn’t get its way. British voters are not going to give power to someone who thinks that’s how it should be used.