Clive Lewis MP told The Telegraph: “Last week felt like it was the starting gun on more Labour MPs beginning to seriously question the Government. You can’t help but think its judgment will now be called into question far more frequently.”

Mr Lewis continued: “On immigration and asylum, why don’t we have safe routes? There’s no safe routes; if you want to stop the boats, establish safe routes.

“Labour should have a practical, humane policy. But any sense of a logical process that is based on human rights, basically what a Labour Government would traditionally be expected to do, is now out of the window.

“Tony Benn was right – if you want to know what your government would do to you if they could get away with it, look at how they treat asylum seekers. That’s what you saw this week with disabled people and you’re seeing it again with this.”

Another Labour MP added that the proposed deal “could be illegal under international law”.

One senior Labour MP and former minister said: “I am very concerned by the proposal. It’s a bit like the debate we had last week about welfare and disability payments. It just doesn’t really seem like a Labour thing to do.

“My view is that we should have more safe routes. But there are a number of my colleagues, particularly those in Red Wall seats, that think being seen to be more conservative on immigration will help them win again next time.

“I know that [Downing Street Chief of Staff] Morgan McSweeney has been a strong voice for moving Right on immigration. Many of us disagree with this approach.”

One MP suggested any revolt over the scheme could be as big as this week’s rebellion over disability benefits which saw 49 rebels vote against the Government’s Bill on welfare reform despite a series of concessions from No 10.