Sir Keir Starmer has sensationally blamed Brexit for Britain’s immigration crisis.

The Prime Minister accused the Conservatives of using the historic decision to quit the bloc as an “open borders experiment”.

Net migration hit an “astonishing” new record of 906,000 last year, heaping more pressure on housing, schools and GP surgeries.

The Office for National Statistics said net migration to the UK hit 906,000 in the year to June 2023, amid an influx of foreign students, a spike in non-EU workers, particularly in the health and social care sectors and the introduction of the Ukraine and Hong Kong refugee visa schemes.

Sir Keir claimed in a Downing Street press conference:

“Time and again the Conservative Party promised they would get the numbers down. Time and again they failed, and now the chorus of excuses has begun.”

He added: “A failure on this scale isn’t just bad luck, it isn’t a global trend or taking your eye off the ball, no this is a different order of failure.

“This happened by design, not accident.

“Policies were reformed deliberately to liberalise immigration, Brexit was used for that purpose to turn Britain into a one nation experiment in open borders.”

Sir Keir said the Government would reform the points-based system and crack down on abuse of visa routes.

He said:

“We will publish a white paper imminently, which sets out a plan to reduce immigration.

“The migration advisory committee is already conducting a review and where we find clear evidence of sectors that are overreliant on immigration, we will reform the points-based system and make sure that applications for the relevant visa routes, whether it’s the skilled worker route or the shortage occupation list, will now come with new expectations on training people here in our country.

“We will also crack down on any abuse of the visa routes.

“For far too long, we’ve been casual about malpractice in our labour market, which sends a clear signal overseas that we’re a soft touch.

“Well, no more – our rules will be enforced.

“Any employers who refuse to play ball, they’ll be banned from hiring overseas labour.”

Sir Keir Starmer has said there has been an “overreliance” on recruiting from abroad as an “easy answer”.

Asked if he was promising “British jobs for British workers” with plans to expect firms that apply for certain visa routes to also train people domestically, Sir Keir said: “For too long we’ve had this overreliance on the easy answer of recruiting from abroad, and that’s got to change. And it’s a two-way street.

“We want to support employers. Of course we do. We want to grow the economy, and I don’t want to make it more difficult for businesses.

“But at the same time, and as I’ve said to them previously, they have to be involved in ensuring we’ve got the skills we need in this country, in the places that we need them.

“That will come partly by devolving skills, getting more employers and local representatives involved in the skills strategies that we need.

“And so, you know, it is right that we have the skills available to people who live here, the opportunities that they want to develop their working lives and give the employers the skills that they need near them for the jobs that they need doing.”

There was a glimmer of good news as the figures fell by 20 per cent in the year to June 2024 – to 728,000.

This was down to restrictions imposed on overseas students and care workers and an increase in the minimum salary threshold, experts said.

Centre for Policy Studies Research Director Karl Williams said: “Today’s net migration figures from the ONS are astonishing. Not only is the figure of 728k for 2023-4 far higher than expected, but numbers for 2022-3 have been revised upwards by 166k to a new record of 906k.

“Net migration in the last four years now stands at over 2.5 million, which represents population growth of 3.8% – equivalent to the combined populations of Leeds, Liverpool, Sheffield, Manchester and Bristol.

“As Kemi Badenoch said yesterday in her speech to the Centre for Policy Studies on the topic, this is an extraordinary and historically unprecedented rate of change.

“For example, our analysis shows that we would have needed to add more than 800,000 to housing targets over those four years – on the methodology used by the Government until recently – just to cope.”

Former Immigration Minister Robert Jenrick said: “The levels of immigration seen in recent times have caused immense and lasting harm.

“They have made us poorer and divided.

“Some parts of our country are unrecognisable from 30 years ago.

“That’s why I secured changes and fought for a legal cap set at the historic norm.

“The UK desperately needs breathing space. Mass migration must end.”

Analysis shows migrants from India, Nigeria, Pakistan, China and Zimbabwe made up the top five nationalities from outside the EU.

Former Home Secretary James Cleverly banned foreign care workers and students from bringing their family members with them.

And Mr Cleverly increased the minimum salary threshold needed to secure a work visa to £38,700.

Migrants must also earn £29,000 before they can bring their partners to the UK, under the changes.

The changes were predicted to bring net migration down by 300,000.

Analysing the figures, migration expert and Conservative MP Neil O’Brien warned that only “500,000” visas issued to 3.1 million people were to work in the UK.

He added the “rest are dependants, students, family, asylum and humanitarian.

“They may well end up working, but the idea some have that migration policy is mainly about work visa is wrong.”

Alp Mehmet, Chair of Migration Watch, said: “Net migration of 728,000, while lower than it was in 2023, is still far too high and unsustainable.

“Moreover, the modest fall has little to do with anything that Sir Keir Starmer and his Home Secretary have done.

“It is now essential that net migration is quickly reduced as close as possible to zero, if we are to avoid further tensions in the housing sector, the NHS and other services already in crisis.

“Meanwhile, the changing nature of society that inevitably follows rapid mass immigration will put the cohesion we have long enjoyed at ever greater risk.”

Mary Gregory, Director of Population Statistics at the ONS, said: “Since 2021, long-term international migration to the UK has been at unprecedented levels.

“This has been driven by a variety of factors, including the war in Ukraine and the effects of the post-Brexit immigration system.

“Pent-up demand for study-related immigration because of travel restrictions during the coronavirus

pandemic also had an impact.

“While remaining high by historic standards, net migration is now beginning to fall and is provisionally down by 20 per cent in the 12 months to June 2024.

“Over that period, we have seen a fall in immigration, driven by declining numbers of dependants on study visas coming from outside the EU.

“Over the first six month of 2024, we are also seeing decreases in the number of people arriving for work-related reasons. This is partly related to policy changes earlier this year and is consistent with visa data published by the Home Office.”

A furious political row erupted on Thursday, with the Conservatives and Labour attacking each other over their plans to deliver on an issue crucial to millions of voters.

Senior Tories warned Sir Keir Starmer’s party will water down measures to slash legal migration.

But Labour said the huge rise in arrivals came under Boris Johnson and Rishi Sunak’s Governments.

Shadow Home Secretary Chris Philp said: “Whilst the 20% reduction – thanks to measures by the last Government – is welcome, these figures are still far too high.

“A new approach is needed, with a hard cap on migrant numbers.

“We need to change our whole approach to immigration, with a low, capped number of high-skill, high-wage workers.

“Labour was wrong to suspend the further restrictions on family visas due to come into force next April.

“I call on Labour to re-instate the measure urgently.”

Former Home Secretary Mr Cleverly said: “Today’s migration figures are the first to show the impact of the changes that I brought in as Home Secretary.

“Numbers are still too high, but we see the first significant downward trend in years.

“Changes that Labour opposed and haven’t fully implemented.”

And Labour’s migration minister, Seema Malhotra, refused to set a target for slashing legal migration.

During a car crash interview on BBC, Ms Malhotra said the Government should not “just pull figures out of the air”.

She added: “My point is this, we want to see net migration coming down but we have to do so in a way that is tackling the causes of net migration.

“Because if much of net migration has been driven by recruiting workers from overseas, you also have to look at what the impact on the economy would be.”

The Labour Party added on Thursday: “The Tories broke the immigration system.

“On their watch, net migration quadrupled in four years to a record high of nearly one million, despite saying they’d lower it to 100,000.

“They are an open borders party.”