In a damning interview Mr Jackson, the former MP for Peterborough and special adviser to David Davis in the Brexit department, described the Brexit decision making process in Theresa May’s government as “polishing an Aston Martin and ending up with a Trabant”.
Speaking to ConHome he admitted that he and Mr Davis made a mistake of thinking continual delay of the department’s Brexit white paper was “cock up and not conspiracy”.
He said: “We assumed it was stasis of the Civil Service, it was incompetence, it was this obsession with write-round and getting everyone in the right place, and actually it wasn’t.”
Then he revealed that in February the Downing Street Europe Unit tried to “bounce” Mr Davis into accepting a plan which would tie Britain to the EU.
Mr Jackson said: “David Davis pushed back on that, said I don’t accept it, I don’t believe it’s the right approach, it’s not in keeping with the Florence speech, it’s not in keeping with the undertakings we’ve made in the general election and at Lancaster House, and it’s not acceptable – it won’t pass the Cabinet and it won’t pass Parliament.”
Having stopped the original plan he said the department thought that “would be the end of matter” by the Europe Unit headed by the controversial permanent secretary Olly Robbins had other ideas.
Mr Jackson said: “There was a decision in the Europe Unit at Number Ten, at the highest level, to circumvent the department.”
The result was the controversial Chequers plan which led to Mr Davis and Boris Johnson along with other junior ministers resigning from the government.
Mr Jackson, who lost his job when Mr Davis walked out of government, said that there had been “constitutional impropriety.”
He said: “I think there’s been constitutional impropriety, in that to wilfully seek to circumvent the department and ministers is quite a serious issue. And it’s actually tragic, because we’ve wasted a huge amount of time on ending up in the cul-de-sac of Chequers.
“I think a lot of the Chequers strategy was predicated on losing the customs union vote, which of course we won by six. So everything has been held back.”