NDP Leader Tom Mulcair is starting to see some of his support ebb away. And that raises questions how he'll fare when his leadership is reviewed in April in Edmonton.

The Niagara Regional Labour Council is the latest to send a message. CTV News reported that yesterday, the labour group's 30 members voted "to not support Tom Mulcair".

The council's vice president, Bruce Allan, told CTV News that Mulcair has provided "the most right-wing leadership the NDP has had".

Meanwhile, two NDP caucus veterans, Niki Ashton and Charlie Angus, have sidestepped reporters' questions about whether they'll support Mulcair at the NDP convention, which runs from April 8 to 10.

Ashton, who represents Churchill, ran for NDP leader in 2012, finishing seventh.

Angus, MP for Timmins-James Bay, says he'll remain neutral because he's the party's caucus chair.

Earlier this week, 37 New Democrats in Quebec, including some former MPs, signed a letter complaining that the party had veered too far toward the political centre. It didn't mention Mulcair by name.

In the October 19 federal election, the NDP won 44 seats and 19.7 percent of the vote. That was a drop of 59 seats from the 2011 election under former NDP leader Jack Layton.

The NDP was leading in national polls at the start of the 2015 campaign.

In November, an upbeat Mulcair spoke about the NDP's successes at the provincial party convention in Vancouver.

Federal New Democrats were elected in 14 of B.C.'s 42 seats, whereas the Liberals won 17 seats in the province.