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Jeremy Corbyn has signed a formal bid to kill off an emergency law denying increased benefits to 150,000 disabled people.

The Labour leader joined Shadow Chancellor John McDonnell, SNP MPs, Lib Dem leader Tim Farron and ex-Deputy Prime Minister Nick Clegg to back the motion on its first day in Parliament.

So far 28 MPs have signed the motion, drawn up by the Lib Dems, to stop legal changes to disability benefit Personal Independence Payment (PIP).

Shadow Work and Pensions Secretary Debbie Abrahams, who has reported the PIP shake-up to the United Nations, has also signed the motion against the law.

Ministers drew up emergency laws to combat two tribunals which said PIP - which funds disabled people's living costs - should be widened.

The tribunals said people who suffer "overwhelming psychological distress" when they leave home should get more cash.

That includes those with autism, dementia, schizophrenia, post-traumatic stress and depression.

Tory MP Heidi Allen warned ministers "have a duty to honour" the tribunals and the Bow Group, a Tory think tank, said ignoring them "gives the Conservative Party a bad name".

Yet the government refused to back down - saying to do so would cost taxpayers £3.7bn by 2022.

And Tory MP Mr Freeman sparked outrage by claiming the "bizarre" judgements had simply helped "people who take pills at home who suffer from anxiety".

Despite the support for the motion it faces a struggle to be accepted - and the last time a similar one succeeded was in 1979.

The legal shake-up is happening via a "Statutory Instrument subject to negative resolution", an obscure piece of law that can only be blocked if MPs "pray" against it.

The law came into effect instantly on February 23, but under Westminster's bizarre system, can be annulled if the House of Commons votes to back a "prayer" within 40 days and nights.

Labour and the Lib Dems both submitted a formal "prayer" to Commons authorities today, and the Lib Dems' - which arrived first - was selected for debate.

Being signed by the Leader of the Opposition makes a prayer more likely to be considered for debate.

But they are still not always guaranteed time in the Commons, even if there is widespread support for them.