Reform UK has pledged to bar foreign nationals from claiming almost all forms of welfare in a move condemned as “senseless and cruel”.

Nigel Farage’s party said it would remove entitlements to Universal Credit, Housing Benefit, Pension Credit, Jobseeker's Allowance, Child Benefit, free childcare and disability benefits if it wins the next general election.

Reform claims the move, which will include those from the EU given ‘settled status’ in the UK after Brexit, would save taxpayers £21 billion a year within five years.

Other parties attacked the plan, warning it would plunge the UK back into years of Brexit negotiations and “strip” support from millions who have worked and paid taxes in the UK for years or even decades.

Reform’s Treasury spokesman Robert Jenrick will formally unveil the policy at a press conference on Monday.

He said: “Forcing British workers to pay for the benefits of foreigners is not just economically illiterate but plain immoral. People are more than happy to support their neighbours in hard times, but the British taxpayer cannot afford to subsidise everyone on the planet, especially those who have not paid in.

"The public have been crying out for this change for decades. Unlike the two old parties, Reform will deliver a system that’s fair for the British people.”

The measures go further than Reform’s previous commitment to cut Universal Credit for foreign nationals, with the party saying it would cover “almost all forms of welfare”.

There would be only a small number of exemptions, including the War Widows Pension and Armed Forces compensation, to “protect the entitlements of those who have served in Britain’s armed forces or built up a life of contributions”.

When it comes to contributions, asked if it would apply to those who have lived and worked in the UK for 25 years, the party said they would retain their state pension but lose access to all other benefits, adding that they would be able to apply for British citizenship.

Reform also appeared to admit it could face delays implementing the policy, saying it would require ministers to renegotiate the post-Brexit withdrawal agreement with the European Union, which protects the social security entitlements of those in the UK before Britain left the bloc.

At Monday’s event, Mr Jenrick is also expected to warn that unless savings are made the benefits bill will “bankrupt Britain and send taxes even higher”.

He will also criticise his former party, the Conservatives, which he left earlier this year, describing them as “two sides of the same coin” with Labour.

A Labour spokesperson hit out at the plans, which he said would "mean ripping up the UK’s Withdrawal Agreement with the EU, plunging the UK back into years of Brexit renegotiations, and stripping support from potentially millions of people who have lawfully lived, worked, and paid taxes in Britain for years, and in many cases decades. That includes people with settled status who are part of our communities, raising families, working, and contributing to our economy.”

He added that the “vast majority” of migrants have no access to the welfare system at all under the existing rules, while ministers are currently tightening the rules.

Liberal Democrat work and pensions spokesperson Steve Darling said:"These proposals are a rehash of the same Conservative playbook, proving the party recycles failed ideas just like it recycles ex-Tory MPs. Broad cuts like this ignore the root causes of the welfare bill, and stripping away vital support that keeps many people working and afloat is both senseless and cruel."

The real way to reduce the welfare bill, he said, was to fix the NHS and social care systems, "giving people the support they need to get back to work and stay there".

Helen Whately, the Tory shadow work and pensions secretary, said the policy was “a cobbled-together announcement which is already unravelling. Their proposals will drag Britain back into Brexit battles with no certainty or success.“

Mothin Ali, the deputy leader of the Greens, said: "Once again, the establishment parties are all trying to outdo each other when it comes to who can be the most xenophobic, who can punch down the hardest to the most vulnerable in our country, and who can cut the most support from disabled people. It is cowardly to take from the most defenceless when we should be taxing the super wealthy including those who are in the privileged position of accepting £5m donations.”

Tom Brufatto, from campaign group Best for Britain, which campaigns for UK-EU reintegration, said: "Our polling shows that people do want to renegotiate our relationship with Europe, but by moving closer, not by damaging ties with vital allies and punishing our neighbours, colleagues, and friends who have settled status here.

“It’s clear after the party’s lacklustre showing in the Clacton by-election, much to Nigel Farage’s evident embarrassment, Reform UK is increasingly out of touch with what Brits really want - which is to get the economy growing again, as independent economic research shows only EU membership can deliver."