Prime Minister Justin Trudeau says with the biggest Canadian grocer now on board, the grocery code of conduct is much more likely to succeed. 

"The fact that Loblaws is now on board means that there's a lot more chances that it's going to move forward, which is what this government has been pushing for for a long time," said Trudeau on Friday, speaking to media after a news conference in Winnipeg.

On Thursday, Loblaw said it would sign on to the grocery code of conduct after months of negotiations to clarify parts of the agreement.

"The code now is fair, and it will not lead to higher prices," Loblaw CEO Per Bank said. 

The code is meant to level the playing field for suppliers and smaller retailers in the Canadian food industry. 

Seeing the grocers sign on to the code is "a big step in the right direction," Trudeau said. 

Last December, Loblaw said it wouldn’t sign the code as it stood then over concerns it would raise prices for Canadians. 

In recent months, pressure has mounted for governments to make the code, which is meant to be voluntary, into law so that all the grocers have to participate. 

The grocers, including Loblaw, have pushed back on allegations that they profited off of food inflation.

Metro and Empire, the other two big Canadian grocers, have already committed to the code, but they have also said that it won't work unless all major players are on board. 

Walmart Canada, which also expressed concern last December that the code would raise prices for Canadians, has not committed to signing it. The company said Thursday that it's reviewing the latest version.

Michael Graydon, the chairman of the interim board for the code, said Thursday that Costco has had "some inquiries around certain aspects" of the code, but he hopes it will also sign on. 

In February, Pierre Riel, chief operating officer of Costco Wholesale Corp.’s international division, told a House of Commons committee studying food prices that if the code is well-defined and its principles are consistent with the wholesaler’s own principles, it will participate.

But at that time, Riel said Costco didn’t have enough detail on how the code would work. 

The news of Loblaw's participation in the code came amid a month-long boycott by some shoppers of all stores owned by the company, as frustration over food prices and industry concentration climbs.