The government is struggling to contain a potential backbench rebellion over its China policy after the Conservative Muslim Forum, the International Bar Association (IBA), and the prime minister’s former envoy on freedom of religious belief backed a move to give the UK courts a say in determining whether countries are committing genocide.

The measure is due in the Commons on Tuesday when the trade bill returns from the Lords where a genocide amendment has been inserted. The amendment has been devised specifically in relation to allegations that China is committing genocide against Uighur people in Xinjiang province, a charge Beijing has repeatedly denied.

It is understood that the former foreign secretary Jeremy Hunt is planning not to back the government either by abstaining or voting against unless further concessions emerge.