Boris Johnson’s plans for strict restrictions on EU immigration after Brexit have been attacked by business chiefs, while Labour warned the NHS would “not survive”.

Long-awaited details of Tory plans for an “Australian-style points system” – which would force lower-skilled migrants to leave the UK after their work visas expire – triggered a backlash.

The Confederation of British Industry criticised “too heavy an emphasis on the brightest and best”, who would face no limits on coming to Britain if Brexit goes ahead.

“Low-level skills are still very much in demand for business,” said Matthew Fell, its chief policy director.

“Many industries are dependent on such workers, from hospitality and construction to agriculture and the care sector.

“Workers needed to boost economic growth must feel welcome in the UK. Until there is more detail, these plans will leave them nervous.”

Labour’s John Ashworth seized on the impact on the NHS, saying: “It’s right that we should absolutely maintain free movement for the National Health Service and the social care sector.

“They are both sectors that literally could not survive if we did not continue to recruit internationally.”

The criticism came after the prime minister announced that he would prevent lower-skilled workers moving to the UK unless there is a “specific shortage” of staff in their sector.

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Those who do arrive would be able to stay in the UK only temporarily – they “will come to do particular jobs and stay for a while”, Mr Johnson said.

The scheme will offer fast-track entry to migrants identified as “exceptional” and to entrepreneurs setting up new businesses, none of whom will require a job offer to move to the country.

A middle category would be “skilled workers” who would require a job offer as well as a specified number of points.

Unveiled four days before election day, the plan seeks to remind voters that immigration, and the pledge to “take back control” of Britain’s borders, was a key driver of the 2016 Brexit vote.

It is very similar to the existing system for non-EU migration, which has seen the number of incomers to Britain rising sharply in recent years.

Nevertheless, the prime minister told Sky News that immigration would be lower in future, saying: “There has been no control at all and I don’t think that is democratically accountable.

“You have got to have a system by which politicians can say to people, well yes we are letting people in but we are doing it in a way that is controlled and checked.”

The Conservatives said the immigration plans would be ready to be introduced from January 2021, although the independent Migration Advisory Committee has yet to start work on the detail.

The Bright Blue liberal Tory think tank said limits on particular categories of migrants were necessary, but Ryan Shorthouse, its director, said: “Those limits should be set after extensive consultation and careful examination of the evidence.”

Meanwhile, the Liberal Democrats warned of a £4,345 bill, over five years, facing EU teachers coming to work in England, because of new visa rules from 2021.

They said the hike in the immigration health surcharge, to £625 a year, would be piled on top of existing fees of £1,220.