Jeremy Corbyn will be pressed this week to agree a points-based system for EU migrants after Brexit.
That means if he was PM no one from the EU could come to Britain to settle without a guaranteed job.
Theresa May could trigger Article 50, beginning the negotiations for Britain to leave the EU, as early as Thursday.
And Mr Corbyn’s MPs are frustrated that the Labour leader has no Brexit plans of his own in place.
Next week former Cabinet minister Liam Byrne will circulate his own policy document among backbenchers in an effort to nudge Mr