Mr Johnson was extremely critical of the Government’s plan not only for a Brexit deal but also the proposed plan for the Irish Backstop.
Writing in the Daily Telegraph, he said: “It was completely wrong of the Government to agree this so-called Northern Irish ‘backstop’ on December 8 last year, and those of us who had doubts at the time have been more than vindicated.
“We were told that it was just a form of words; we were told that it was merely temporary; we were told that these were redundant phrases that would never be invoked.
“As it is, that Irish backstop has been turned into the means of frustrating Brexit, because the alternative is even worse.”
The former Foreign Secretary also took aim at the Prime Minister’s Chequers plan.
He said the proposed deal would mean that the UK would “effectively remain in the customs union and single market”.
Mr Johnson added: “This is a catastrophe for Brexit, and makes a mockery of the project.”
According to the politician, this would mean the UK could be used as a bargaining chip during EU negotiations with other powers, such as the US and China, without having a say in the deal.
Mr Johnson added these negotiations would not necessarily have to benefit the UK and could even have an adverse effect.
He said: “It is our markets that will be treated as bargaining chips, by the EU, and one can easily imagine that – without any kind of political consent from this country – the EU might decide to open up, say, healthcare markets to American providers.
“Or they might agree any number of deals that damaged UK interests.”
The former Mayor of London later described the “Facilitated Customs Arrangement” as being a “non-starter”.
He argued once the UK paid the £39billion to temporarily remain in the Customs Union, then “the EU will have no incentive to negotiate anything else”.
While discussing the issue of Northern Ireland, Mr Johnson said if Northern Ireland were to become a separate economic entity from the UK, then “we would be trading Northern Irish MPs as somehow second-class legislators”.
He added that while the UK would be able to participate in free trade deals, “Northern Ireland would not be able to take part”.
Ultimately, Mr Johnson argued for the end of the backstop and for a Canada-style trade arrangement to be made.
He said: “It is time to scrap the backstop, and simply agree what is manifestly the case – that no one wants any new physical checks in the Northern Irish border, and nor is there any need for them.”
Mr Johnson later added: “It is the Super Canada, zero tariff, zero quota, free trade deal at the heart of a deep and special partnership.
“It is right for both sides, and it is time to go for it.”