London: Low-skilled migrants will face sweeping new restrictions on moving to Britain, under a radical post-Brexit immigration shake-up planned by Boris Johnson.

The prime minister announces today (Sunday) that he is planning to prevent lower-skilled workers moving to the UK unless there is a “specific shortage” of staff in their sector, such as construction. Those who arrive will only be able to stay in the UK temporarily.

The plan, made public in the final days of the general election campaign, forms the centrepiece of Johnson’s proposals for an Australian-style points-based immigration system after the UK’s planned exit from the EU next year. Immigration was a key factor of the 2016 Brexit vote and the official Leave campaign led by Mr Johnson pledged to “take back control” of Britain’s borders.

The scheme will offer fast-track-entry to migrants identified as high skilled or “exceptional”, including those with “world-leading awards” and sponsored entrepreneurs setting up new businesses — none of whom will require a job offer to move to the country. Anyone convicted of a serious crime will also be banned from entering the country, after the free movement of EU citizens ends following the UK’s exit from the EU.

The prime minister, who made a campaign stop at Neasden temple with his girlfriend, Carrie Symonds, last night — their first joint appearance of the campaign trail — announced the plans as he released an open letter to voters warning that Thursday’s election will “shape future decades” and urging supporters to ensure that their family and friends “understand what is at stake”.

A Savanta ComRes poll for The Sunday Telegraph shows a narrowing of the Conservative lead, to eight points, which would put the party on course for a majority of 14.

The Conservatives said that the immigration plans would be rolled out by an expert implementation group from January 2021 — immediately after the UK’s planned exit from the EU. The proposals expand on the pledge to introduce a points-based system which was included in the Tory election manifesto. The manifesto said: “There will be fewer lower-skilled migrants and overall numbers will come down.”

Today the party reveals that its scheme would involve three categories of migrants who could apply to enter Britain: those with “exceptional talent”,

skilled workers who will require a job offer in addition to a specified number of points, and those in lower skilled sectors such as construction, who will only be able to enter the country as a result of labour shortages in that sector.

Johnson is planning to expand the independent Migration Advisory Committee and require the body to publish an annual report on how to reduce overall immigration while addressing “emerging gaps” in the labour market.

The Conservatives would also introduce a “digital immigration status” from 2022, allowing individuals to easily prove their right to be in the country in dealings with employers and the NHS, and making it easier for officials to crack down on those who overstay illegally.

The PM and his partner Carrie Symonds made their first public appearance together on the campaign trail last night at Neasden Hindu temple in London. The pair attended celebrations for what would have been the 98th birthday of guru Pramukh Swami Maharaj. Ms Symonds wore a fuschia sari, with both sporting bindis on their foreheads.

In his letter to the nation, Johnson says that the new system would “allow us to make it easier for the brightest talent from around the world to come here. But it will put in place tough new checks to ensure that lower skilled -migrants only enter the UK if there is a specific shortage of workers and that their stay will only be temporary. Everyone who comes to the UK will contribute to our NHS from day one — that is only fair.”

Priti Patel, the Home Secretary, said: “The vote to leave the EU was a vote to take back control of our borders, and that is exactly what a Conservative majority government will do by getting Brexit done and ending freedom of movement. Immigration will finally be subject to democratic control. We will be able to create a fairer system, which will attract the brightest and the best from around the world to come here and contribute to our society and economy, while getting overall immigration down. Corbyn’s Labour want uncontrolled and unlimited immigration, placing huge strain on public services like our NHS.”

Under the plans, there will be no cap on the numbers of migrants in the “exceptional talent” category and those individuals will no longer need an offer of employment to arrive in the UK.

The Conservatives are also proposing to expand the number of British universities and research institutes that can endorse candidates for this category of visa and any individual endorsed as a “recognised leader” or “emerging leader” will be awarded additional points under the system.

The plan includes speeding up the sponsorship process for skilled workers to reduce the amount of time it takes to fill gaps in the labour market. The Tories say that applications for general work visas can currently take up to 20 weeks. The Migration -Advisory -Committee (MAC) would be asked to report annually on whether there are shortages or excesses of skilled migration, to allow ministers to decide whether there is a need to cap numbers or create incentives to increase the number of those benefiting from these visas.

The third category, for lower skilled workers, will be based on a principle that “there will not be a general route for low or unskilled workers, unless there is a specific labour market shortage” identified by the MAC.

All visas under this category will be time-limited, with a cap likely not to exceed five years and “will typically not lead to settlement”, according to the Conservative plans.

This category will include capped schemes to fill specific labour shortages, such as the Seasonal Agricultural Workers’ scheme, which The Sunday Telegraph has disclosed will be open to 10,000 workers next year — an increase from 2,500 this year.

Johnson likens this election to the 1945 poll, when “the Conservative Party had lost its way and the Attlee -government created the NHS — one of the great achievements in British -politics in the 20th Century.

Launching his own pitch to voters in the final days of the campaign, Mr Corbyn said: “The most powerful people in Britain — the billionaires, the tax dodgers, the bad bosses and the big polluters — will do anything to stop real change, because the system is rigged in their favour and they don’t want to pay their fair share of tax.”