Brexit may have been the making of Boris Johnson – but this is why it will also be his undoing

Johnson’s reign will be defined as an example of ambition alone not being enough. The political reality of Brexit will simply be too difficult for him to surmount

Prime minister Boris Johnson spared no time in sacking a record number of ministers to create his no-deal cabinet. He has reformed his Vote Leave campaign band for a reunion tour with co-chair Michael Gove as deputy and strategist Dominic Cummings as chief of staff.

These changes bring the quick win for Johnson’s supporters of showing a clear break from the more centrist Tory governments of the past led by David Cameron and Theresa May. Those who backed Boris will feel he’s honouring his promise to make Brexit happen by Halloween. But I’m afraid the real picture is more trick than treat.

Johnson has been in the enviable position of making promises that he never had to keep. As a backbench opponent of fellow Old Etonian Cameron, Johnson had the luxury of having no responsibility for delivering the referendum result he campaigned for.

When later made foreign secretary, Johnson’s only contribution to negotiating a deal with the EU was to resign immediately rather than help forge a solution. At every turn, Johnson would rather wound his party’s leader to better position his succession than heal the deep divisions across the country he did so much to create.

Now his turn has come – and the time for his reckoning.

The prime minister has promised the public many things, not least an extra £350m per week for the NHS, that were neither honest nor realistic. His supporters have drunk the kool aid believing a combination of being more optimistic about Brexit and keeping a no deal option on the table are enough to bring the EU back to the negotiating table on our terms.

If wishful thinking was enough, Brexit would have happened by now. May’s failure to deliver was not because she didn’t want a deal but rather because few others supported the deal she agreed. The devil was very much in the details. May’s having a deal wasn’t enough. For more extreme Brexiteers, the only deal they wanted was no deal at all.

Johnson believes a new deal is possible. This is probably fanciful as the EU has already rejected this option, but even if there was flexibility the PM will fail like May over the details. His alternative vision is surprisingly shallow. A main aim is simply to avoid being locked into the so-called Irish backstop, but without any existing technology or means to do so. Such pigs can’t fly – making the possibility of amending May’s deal virtually nil.

The more significant difference in Johnson’s approach is his commitment to threatening the EU with no deal if negotiations fail by 31 October. No deal has become the new priority for Johnson’s government. For many Leavers, this is the key to unlocking a better outcome. But how credible is this second bout of wishful thinking?

No deal is often characterised by its costs – and how the EU’s economy will be hit hard too so it should serve as a strong deterrent. But this is only a partial picture that masks why no deal is not a viable option.

The UK’s EU membership has created an interlocking network of agencies and official departments that help maintain the thousands of EU regulations currently in place. Leaving without a deal in 99 days means the UK must recreate this work in about three months so it can hit the ground running. This means hundreds of people recruited, put in post and ready to go.

This is the stuff of unicorns frolicking through fields of wheat while painting red buses made from old wine crates. It’s nonsense, and is an indication of how little the new prime minister grasps the enormity of the challenge before him as only someone weak on details could be led to believe.

In assembling a cabinet signed up to a strategy of wishful thinking with an empty threat, Johnson’s new look team will likely follow the same old fate of the previous government in failing to deliver Brexit. When I predicted it would not happen, I could not see Boris’s rise. Yet the sheer complexity of making the legal and institutional changes required remain such that Brexit will stay out of reach for the foreseeable future.

On his nationwide tour, the promise of a Brexit “by any means necessary” is already unravelling. Johnson is now saying Britain may stay in the single market for two or more years. This U-turn is a product of watching the pound slip to a new low thanks to Boris’s boastful bluster now coming back to haunt him well before his Halloween deadline.

But those who backed Boris never thought he’d blink within days – however nothing speaks more of the UK’s declining global influence thanks to Brexit than such policy shape-shifting over Brexit. This wannabe emperor wears no clothes.

As a former classics student, Johnson may delight in tales of tragedy but his is next. It is all too clear from day one that – like Gordon Brown or Theresa May who had the ambition to become prime minister but lacked a clear, distinctive vision for their premiership – Johnson’s reign will be defined as another opportunity lost where ambition alone isn’t enough. Boris shall find that getting fellow Tories to install him in 10 Downing Street is easier than delivering leaving the EU. Brexit has been the making of him – and his undoing.

Thom Brooks is dean of Durham Law School and professor of law and government