Canada's largest oil refinery will announce details this week of what it calls the “largest maintenance project in the company's history.”

A notice from Irving Oil says the project, which will be revealed Thursday in Saint John, will be one of the largest private sector investments in Canada this year.

Premier Brian Gallant has been hinting for days that a major announcement is coming that could create thousands of jobs in southwestern New Brunswick.

The premier told a business audience Tuesday night in St. Stephen that an announcement is coming this week that will mean thousands of jobs and will fill hotel rooms in southwest New Brunswick.

When asked Wednesday about the Irving announcement, Gallant only smiled and said “any announcement that stimulates the economy and creates jobs is welcome.”

"We need to focus on ensuring there are opportunities for New Brunswickers here to live here, to come back here, and to raise their families here," Gallant said.

"Anything that will help us create jobs whether it's in the short term or the long term is welcome as long as it's done in the right way."

That started a lot of speculation.

“The phone has been busy this morning,” said Stephen Beatteay with the Saint John Construction Association, “People wanting to know if the announcement has been made.”

“It’s very big,” said Jodi Waring with the Plumbers and Pipefitters Union. “Irving Oil has big plans and they want to accomplish a lot of work, and they’re not going to have a problem.”

Gallant said the Irving project is a private sector investment, without government funding.

Mike Belliveau with Hospitality Saint John says hotels will benefit from the deal.

“They’re staying for multiple days, so they’re experiencing the city, taking in some attractions and going to restaurants,” he said.

The Irving Oil refinery opened in 1960 and produces more than 300,000 barrels of refined product each day.

The facility has been upgraded numerous times over the years, including a $1.5 billion project in 2000.

With files from CTV Atlantic’s Mike Cameron and the Canadian Press.