Boris Johnson is drawing up plans to impose strict new restrictions on EU immigration by 2021, two years earlier than promised by Theresa May.

New proposals are understood to be in the works to implement restrictions on lower-skilled EU migrants on the first day after the Brexit transition period ends, removing a temporary extension of current rules to 2023 sought by business groups.

Priti Patel, the home secretary, is expected to present the blueprint to cabinet this week, which would give businesses and workers less than a year to prepare for a major overhaul of the immigration system.

“We need to deliver change and businesses need to be prepared for uncontrolled migration of low-skilled workers to end this year,” a No 10 source told The Sunday Telegraph.

Labour described the move as “ill-informed and reactionary” and warned that changes would wreak havoc with staffing in the NHS and public services, as well as key private sector industries.

It comes after Sajid Javid fired off a warning to manufacturers that “there will be no alignment” with EU rules after Brexit – and admitted that some firms would be hit by the UK’s departure from the bloc.

Mr Johnson unveiled long-awaited details of his plans for an “Australian-style points system” days before his election victory.

Under the three-tier system, “highly-skilled” workers would be fast-tracked with a second tier for “skilled workers” who can enter the UK for a job offer. The third group of low-skilled workers would only be able to stay if there were staff shortages.

Business leaders sounded the alarm over restrictions to foreign workers who make up a critical part of the workforce in the NHS and social care, as well as in hospitality and on farms.

Ms May’s immigration white paper in 2018, proposed a “time-limited route for temporary short-term workers” to mitigate the “challenges faced by employers who would find it difficult immediately to adapt” to new immigration rules.

Bizarre: Boris Johnson drives 'Brexit' digger through boxes Show all 8 1 /8 Bizarre: Boris Johnson drives 'Brexit' digger through boxes Bizarre: Boris Johnson drives 'Brexit' digger through boxes Conservative party leader Boris Johnson drives a JCB through a fake wall POOL/AFP via Getty Images Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson during a visit to JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson sits in a cab of a JCB during a visit to its cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Britain, December 10, 2019. Ben Stansall/AFP/Pool via REUTERS POOL REUTERS Bizarre: Boris Johnson drives 'Brexit' digger through boxes A sign made for a visit by Prime Minister Boris Johnson to the JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson reacts as he sits in the cab of a drives a Union flag-themed JCB, after driving through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty

But a No 10 source told the paper: “As we leave the EU in just over 10 days’ time, we have an unprecedented opportunity to change the way our immigration system works.

“There is a clear drive for talented and skilled workers from around the world to come to the UK, but we also need to see a reduction in the number of unskilled workers and those without a job entering the UK and that’s why this will be coming to an end when the transition period ends in December.”

Mr Johnson will make a final decision once he has received recommendations from the government’s Migration Advisory Committee, which are expected within weeks.

Diane Abbott, the shadow home secretary, said: “This is an ill-informed and reactionary policy that will damage us all, damaging to everything from the NHS to other public services and some of our key private sector industries.

“Ministers talk about ending uncontrolled migration when they have been in office for 10 years. In reality this is just a new twist in the long Tory campaign against migrants, scapegoating them for the terrible effects of Tory policies.”

Liberal Democrat home affairs spokesperson Christine Jardine said the changes were “utterly unworkable” and impossible to implement in time.

“Decisions like this make it loud and clear that this Conservative government has no intention off ending the hostile environment,” she said.

“It’s a national embarrassment. For business and our economy, such draconian changes to immigration rules is utterly unworkable. To think the Home Office could implement the changes in the time given is a joke.”

Meanwhile, ministers have reportedly kick-started no-deal planning once more amid fears trade talks with Brussels could collapse.

Whitehall’s EU Exit Operations committee, which is chaired by Michael Gove, met on Thursday to discuss preparations for a no deal at the end of the year, according to the Mail on Sunday.

The prime minister is facing a new Brexit cliff edge in December when the transition period ends – and the UK could crash out of the EU without a trade agreement.