Three opposition parties joined forces on Parliament Hill on Wednesday to call for the withdrawal of Bill C-39, arguing the federal bill should not proceed in its current form.

Bloc Quebecois MP Patrick Bonin, NDP parliamentary leader Don Davies and Green Party Leader Elizabeth May made the call together, an unusual cross-party alignment that signals the breadth of opposition the bill has drawn outside government ranks.

The MPs cited concerns about the bill's impact on Indigenous rights, environmental protections and workers' rights. Those three themes have been recurring points of contention in federal legislation this Parliament, and the joint appearance was designed to show they cut across party lines.

The government had not announced any withdrawal in response by Wednesday evening. Whether the bill is pulled, amended or pushed ahead will now be a test of how much weight a united opposition front carries on a file where Indigenous and labour voices have also been pressing for changes.