Tom Mulcair is the leader to take the NDP forward, reads the subject line of an email Ken Neumann — national director for Canada of the United Steelworkers — wrote to key members of the union earlier this week.

Weeks ahead of the NDP convention in Edmonton that will decide Mulcair’s fate as leader of the party, Neumann’s support pushes back against other voices in the labour movement including Sid Ryan, a former president of the Ontario Federation of Labour, looking for a Bernie Sanders or Jeremy Corbyn type to replace him.

Ryan and Barry Weisleder, the chair of the NDP socialist caucus, have mounted a very vocal campaign in recent days criticizing both Mulcair’s leadership and the policies put forward during the last campaign.

Neumann has stepped up in his defence.

“Many of us share the belief that there are things that could have been done better during the last campaign, but public attacks like the ones Sid and Barry are launching are not how we build a strong social democratic movement,” Neumann wrote in an email obtained by iPolitics.

He then listed the social democratic policies Mulcair championed in the last campaign: a national childcare plan, a national pharmacare plan, a $15 federal minimum wage, labour law reforms, the repeal of C-51 and defeat of the Trans-Pacific Partnership.

“To see movement on these important issues, we need a tough, articulate and experienced question period fighter like Tom Mulcair to lead our movement and hold Justin Trudeau to account,” he wrote.

“Liberals do not adopt progressive policies unless they are forced by the public to do it. It is Tom’s brand of fiery questions in the house that will help move our issues forward. That is why I am proud to stand by Tom and will be voting for him at convention in April.”

Neumann’s letter followed an appearance on CTV’s Power Play in which he debated Ryan on the subject.

Other major Canadian unions, however, are leaving the decision to their members or avoiding the subject altogether.

Robyn Benson, national president of the Public Service Alliance of Canada, said they won’t be taking a position as an organization.

“NDP convention delegates who are PSAC members will caucus at the convention to discuss the leadership review and other important issues up for debate. PSAC as an organization will not be taking a position on the leadership review,” she said in an emailed statement.

For their part, Unifor, the largest private sector union, told iPolitics they haven’t made any decision on the NDP leadership review.

Under the NDP’s constitution, Mulcair will need 50 per cent plus one of the delegates to avoid triggering an automatic leadership election within a year. But party President Rebecca Blaikie said in February that he’d need 70 per cent “in order to stay”.

According to someone informed about delegates’ intentions, roughly 20 per cent remain undecided. But there’s also a certain amount of election fatigue and, at the moment, no real alternative to Mulcair.

While some NDP MPs have recently expressed their support for Mulcair publicly — most notably Nathan Cullen, who ran against him for the leadership; Tracey Ramsey, the party’s trade critic; and Alex Boulerice, the party’s ethics critic and Quebec lieutenant — others have been more circumspect.

Niki Ashton, who also ran for the leadership in 2012, was evasive with reporters on Tuesday.

“This is not about a person or a personality,” she said. “Those processes are in place and will take their course.”

Later in the day, Élaine Michaud, who lost her Portneuf—Jacques-Cartier seat in October, told CBC she hasn’t made up her mind yet on whether to support Mulcair’s leadership at the convention.

“I’m going to very honest, my decision has not been taken yet as to my vote,” she said.

Some NDP MPs who didn’t wish to be quoted have told iPolitics that they’d prefer to wait to see how the Liberal government performs over the next year and reevaluate Mulcair’s leadership then.

The NDP constitution requires a biennial convention every two years, so even if Mulcair gets a good result he’ll still have to face another leadership review before the next federal election.

But launching a leadership contest in the spring of 2018 wouldn’t leave much time to pick a new leader and introduce them to Canadians ahead of the October 2019 fixed election.

The other option under the constitution is a special convention, which has to be requested by a majority of electoral district associations in a majority of provinces and territories.

For those NDP delegates who aren’t sure whether Mulcair should continue as leader but who also aren’t quite ready to show him the exit yet, that remains a option. Though hardly an ideal one.