Britain desperately needs immigration because “we native Brits are so bloody stupid”, the lord who helped draft Article 50 has said.

Lord (John) Kerr of Kinlochard said Britain needs more intelligent migrants to “wake up” the native population, and accused UKIP’s Nigel Farage of “xenophobia and racism” during the referendum campaign.

His comments generated such outrage that Conservative MP Peter Lilley walked out of the event, describing Lord Kerr’s views as “odious”.

The crossbench peer is a former diplomat who helped co-write the EU’s Lisbon Treaty, whose Article 50 sets out the process by which a member state can quit the union.

He said during his speech on Thursday that mass immigration was a good thing, and that people who voted for Brexit on the basis migration was too high were misled.

“There’s a much deeper argument to have – and that is about whether immigration is good for you or bad for you. In my view, immigration is the thing that keeps this country running.

“We native Brits are so bloody stupid that we need an injection of intelligent people, young people from outside who come in and wake us up from time to time.”

The Mail reports that the peer, who supported Britain staying in the EU, added that Theresa May’s determination to limit immigration as part of the Brexit deal meant Britain was heading for a “very, very hard and unpleasant Brexit”.

“And why?” he added. “Because it rests on a fundamental preconception which none of the three parties were brave enough to address.

“That’s the principal problem: not the reality of immigration, which is a good thing; but the perception of immigration in the country and that pusillanimity of politicians.”

In response to the comments, Conservative MP Peter Lilley said: “I think these comments revealed the contempt that some Eurocrats like Lord Kerr have for ordinary British people.

“They think they are there to rule the country and hugely resent any interference by the electorate.”

He even said he had considered reporting Lord Kerr for hate speech, but decided not to as “I don’t like the law to prosecute opinions however odious”.

He also accused the lord of “profound stupidity”, adding: “To say the British people are stupid and then to suggest that housing has nothing to do with immigration displays such profound stupidity that one wonders why he lectures other people.

“It is particularly odd coming from a man who is racially abusive of British people.”