The job of Brexit minister David Davis is being undermined Prime Minister Theresa May's lack of "flexibility", his former chief of staff has claimed.
One of the issues is May's insistence that the European Court of Justice (ECJ) has no jurisdiction in the UK after Britain leaves the EU.
However, the EU wants the ECJ to continue to offer protection to UK citizens and uphold the rules of the single market. Meanwhile, Davis wants to replace the ECJ influence with new international body to settle disputes between the UK and the EU.
In an interview to be broadcast later this morning, Chapman will say: "She's set a red line effectively for a conference speech that hamstrung these negotiations in my view.
"There have been red lines that have been set for him that make the job he has to do very difficult."
And if May's Brexit deal may struggle to get the backing from MPs, said Chapman, who now works for PR firm Bell Pottinger. He said:
If she doesn't, in my point of view, show more flexibility, show more pragmatism than she did demonstrate in the Home Office, she won't get this stuff through parliament.