Keir Starmer insisted a crunch Commons vote on benefits reforms will go ahead next week despite looking doomed to a disastrous defeat.
The PM is looking down the barrel of a huge rebellion with nearly 130 MPs having signed an amendment that would effectively kill off flagship legislation.
Rachel Reeves has been ringing round backbenchers warning that losing the curbs to health and disability benefits would 'devastate' the government.
Even with the proposed £5billion of savings welfare costs will still be soaring, and economists believe she will have to hike taxes in the Autumn to balance the books.
The the scale of the insurrection is enough to overturn Labour's huge majority. The last time a government Bill was lost at second reading was 1986.
