NICOLA Blackwood is among Conservative MPs who are poised to rebel against a £1.3bn Government cut to disability benefits.

The MP for Oxford West and Abingdon confirmed she had signed a letter to Chancellor George Osborne with "a significant number" of her backbench colleagues, raising concerns about the move.

Ministers are facing a growing row as the rebels, led by Andrew Percy MP, are warning the squeeze on personal independence payments (PIPs) sends out the wrong message.

Last night Miss Blackwood told the Oxford Mail: "I have joined other Conservative MPs asking the Chancellor to look again at the PIP proposals because I have always believed that even in difficult fiscal times we must do our utmost to protect the most vulnerable.

"Whilst it is of course welcome that overall spending on the main disability benefits is increasing over the course of this Parliament, I have made clear my concerns to ministers and the whips about the cumulative impact these changes will have on disabled people coming so soon after the ESA and other reforms."

Government officials expect up to 640,000 people to be affected by tighter criteria, brought forward after a review by health professionals found people were being awarded points for aids and appliances already in their homes or provided by the NHS and councils.

Ministers insist overall spending on disability benefits is going up and the changes are needed to make sure the cash is better targeted to those in most need.

But Mr Percy said the measure was a cost-saving one and would not improve support.

He warned the plans were on course to suffer defeat in the House of Commons if Mr Osborne tried to push them through using the Government's majority of 17.

He added: "You don't need very many for this to be a problem of parliamentary arithmetic."

On BBC Question Time last night, Education Secretary Nicky Morgan said that the government was "continuing the conversation" about the decision.

But this morning it was reported that the Government had hardened its position.