The European Parliament’s Brexit coordinator has said he will “never” allow the UK to control its own borders, claiming a system based on allowing in professionals and people with the skills the nation needs amounts to “discrimination”.

Ranting before MEPs on Tuesday, arch-liberal and federalist Guy Verhofstadt also personally attacked senior members of the Tory Party and rejected proposals from leadership favourite Boris Johnson to extend the Article 50 process.

He claimed that “enough mess has been created” by Brexit already, adding “let’s stop it”, before deploring the actions of the Conservative Party in recent weeks as “insane”.

On Tuesday, home secretary Sajid Javid announced plans to prioritise immigrants’ skills, rather than their country of origin, in a post-Brexit shake-up of the visa system and immigration.

The government claimed the move would bring down numbers by capping unskilled migration. However, critics said numbers could go up as more skilled migrants would be allowed in as businesses would be handed more power.

Mr Verhofstadt rejected the proposals outright, insisting the bloc “will never accept discrimination based on skills and nationality, as Mr Javid this morning proposed”.

Launching an extraordinary attack on senior Conservatives, he continued: “When you see these insane notions of some Tory politicians of the last days: Boris Johnson, his latest invention, you have seen that?

“He will solve the problem by building a bridge between the UK mainland and Ireland. Mr Boris Johnson is more known for burning bridges than for building bridges!

“Then there’s Mr Rees-Mogg who’s saying ‘yeah, I have the proposals for the future of Brexit, ordinary citizens and their savings can be secure after Brexit!’ and in the meantime he’s opening for himself an investment fund in Ireland, to transfer his money to Ireland.”

He added: “Jeremy Hunt, who is comparing the European Union with the Soviet Union. But in his case that is not so abnormal: he has once even confused Japan with China. This is not the first time this is happening.

“The previous time he was insulting his wife, but this time it’s something far more different: he’s insulting not us, but millions of ordinary citizens who have lived under Soviet rule for so long.

“That is, in fact, a point on which he has to apologise, I think because we cannot take it as such a thing he said.”