Michael Gove has promised that the UK will have struck a trade deal with the EU by the end of 2020 and will not extend its transition period, despite Boris Johnson having failed to meet his previous Brexit deadline.

The cabinet minister confirmed the pledge tying a Conservative government’s hands if the party wins a majority, saying it was realistic because Johnson had secured a deal with the EU within 90 days. In fact, Johnson’s deal is heavily based on Theresa May’s deal, which took about 18 months to negotiate, and most international trade deals take years to finalise.

The Cabinet Office minister set out the promise on BBC Radio 4’s Today programme, where he also unleashed a series of personal attacks on Jeremy Corbyn for taking Vladimir Putin’s side and being a “non-league player” in politics against Johnson’s “Premiership goalscorer” abilities.

He branded Corbyn’s claim that he could renegotiate the Brexit deal within three months as “beyond the realms of fantasy and science fiction and fairytale”, branding him a “terminally weak leader”.

Gove also questioned how Labour could do a deal with the EU and then campaign against it, singling out Diane Abbott, the shadow home secretary, as having said she would back remain even though John McDonnell, Keir Starmer and Emily Thornberry have all taken the same position.

Pressed on difficult issues for the Conservatives, Gove said there would be a full independent inquiry into Islamophobia but he could not say who would run it and he defended the prime minister’s refusal to publish a report about Russian interference in British democracy, saying it was going through the usual procedures.

With the gloves now off in the election campaign, Labour is also launching its own assault on Johnson’s aim to have a quick post-Brexit trade deal with the US, which could allow maggots in orange juice and rat hairs in paprika.

Keir Starmer, the shadow Brexit secretary, said Johnson’s plans for a trade deal would lead to lower food standards and could bring higher prices for medicines.

“If you vote for the Conservative party, you get a hard Brexit which I think will damage our economy. It will also lead to the breakup of the union,” he said.

“That’s one side. The other side [Lib Dems], you have got revoke [article 50] – I know a lot of people who voted remain, and are passionate about remain, who don’t think revoke is the right thing to do.”

He continued: “[With Labour] you are voting for the chance for the public to decide the future. You are voting for the public to be asked: ‘Do you want to leave with this deal, or do you want to remain?’”

He said it did not matter where Corbyn and he personally stood on the issue of leaving with a Labour deal or remaining in the EU, although he has always made clear he would want to campaign to stay in the bloc.