The union representing Irving Shipyard workers lifted its strike threat Friday and will return to the bargaining table with Irving Shipbuilding on Monday.

The union will be in a legal strike position Saturday but said it believes it is in the best interest of members, the company and the country to avoid a work stoppage.

"Irving has informed us they are prepared to make a good-faith effort to address some of the concerns raised by our members, so on this basis we will extend the strike deadline and return to the table," said Adam Hersey of Unifor Local MWF 1 in a statement released Friday afternoon.

Local MWF 1 represents more than 800 members working on the multi-billion dollar federal shipbuilding deal.

The union's bargaining team reached a tentative deal with Irving, only to see 75 per cent of union members reject it Wednesday.

Did union exec misread membership?

Maurice Mazerolle, the director at Ryerson University's Centre for Labour Management Relations, said it's unusual for a union-backed deal to get rejected.

"You could argue that the [union] executive misread the membership," he said in a phone interview Friday.

Mazerolle has negotiated on behalf of management in the past, but isn't involved in this case.

"It's not fun because then [the union] comes back, and you don't have anything left to give because you gave it at the table to make the deal."

He added: "Quite often rejection of the recommended agreement results in the negotiating team resigning and usually a new team is elected to go in and try to deliver what the members want."

Chad Johnston, lead negotiator for the union, will return to the bargaining table with Irving on Monday. (CBC)

That tends to be a bad sign, he said, as it suggests some union members are "stoking the expectations" unrealistically and they might struggle to reach a deal with Irving. But he's seen a change of people lead to a new deal. Either way, the bargaining teams on both sides need to know exactly why the membership rejected it.

Unifor said it will send the same negotiating team to the table.

'You can't subdivide a principle'

Stephanie Ross, an associate professor in the School of Labour Studies at MacMaster University, agreed it's rare to see membership reject a union-backed deal.

"But I think they're becoming more common because it is becoming more difficult for bargaining teams to make gains without having to threaten strike action," she said.

Ross said a strike mandate only expires when a new deal is ratified. The union could still hold a one-day strike, a rotating strike, or stay out until they get a new deal.

Irving could turn the tables, too. "Once a legal strike deadline comes, it's also a legal lockout deadline."

Mazerolle said it could prove hard for the two sides to agree in this case because the union says it's not about money, but about respect in the workplace and too many subcontractors and temporary foreign workers.

The union brought strike placards to a news conference earlier this week. (CBC)

"Money is one thing. You can always find money," he said. "The worst negotiations are when you're on strike over a principle — like subcontracting, or job security, or union work versus non-union work. You can't subdivide a principle."

He said the two sides could agree to something like a one-year freeze on hiring more temporary foreign workers or subcontractors, or giving the union preference on those jobs.

Those workers could have to pay dues to the union, or have a limit on how many days they can work before joining the union. Irving and the union could also set up a joint task force to look for a long-term solution as work continues.

"There has to be a gesture toward those issues, or it's not going to settle," Mazerolle said.

Could sick days play a role?

Ross said talks are crucial, as strikes are hard on workers and managers. She said the wide range of union membership concerns could have fuelled the rejection.

"People are angry above a dollars-and-sense calculation," she said. "They want the employer to come back with a deal that restores the recognition of the importance of workers."

One bargaining chip could be the lack of sick days for workers. Ross said that the men and women who physically build the ships and don't get sick days would likely resent that office-based managers do get sick days. If Irving could give union workers sick days, she said that could be enough to get a successful ratification vote.

The union says between 150 and 300 contractors are in the shipyard at any given time, along with a smaller number of temporary foreign workers.

Irving said it has 18 internationally-recruited shipbuilders working now, making up two per cent of the workforce. They are all union members and working to become Canadian citizens, spokesman Sean Lewis said Friday.

He wouldn't give a number for subcontractors not directly employed by Irving.