CTV News has learned the federal labour minister is expected to step in and overrule the leadership of Ottawa's striking Amalgamated Transit Union by ordering transit workers to vote on the city's latest contract offer, which could put an end to a three-week-old transit strike that has crippled the nation's capital.

The City of Ottawa asked Rona Ambrose to invoke a rarely used section of the labour code after talks between the two sides broke off Christmas Eve.

Senior Conservative sources told CTV News on Monday the labour minister could order the union to put the issue to a vote as early as Tuesday.

It's a move Ottawa Mayor Larry O'Brien says he thinks will be the fastest way to end the dispute.

"If they don't vote to approve it, we have a different issue to deal with. But we believe hardworking members of ATU 279 will approve our offer and accept our offer and get back to work," said O'Brien.

The key issue of the dispute remains control over bus driver scheduling, which OC Transpo management wants to take back from drivers.

Although the city wants transit workers to vote on their latest offer, many drivers marching the picket lines Monday told CTV Ottawa they will reject the proposal.

"No way, no way . . . not going to vote for it," said one striking bus driver.

"The drivers aren't going to accept it. We say, we stay out until the scheduling issue is off the table."

For many businesses across the city, the public transit strike has already caused irreversible damage.

"It hurts to the point that if this goes on long enough, you're not going to be able to pay your bills," said Ottawa business owner Zadek Ramowski.

Even if the strike is settled soon, it will take several days for buses to get rolling on Ottawa streets.

About 2,300 OC Transpo drivers, dispatchers and mechanics walked off the job Dec. 10 after working without a contract since April.

With a report from CTV Ottawa's Vanessa Lee