Ottawa's Amalgamated Transit Union is urging the federal labour minister to reject the city's request to force bus drivers to vote on the city's latest contract offer.

"We would rather be at the table instead of having a third party decide if we're going to have a vote," said Jim Haddad, the transit union's secretary-treasurer.

However, senior Conservative sources told CTV News on Monday that Rona Ambrose plans to step in and overrule the union executive if it did not let their membership vote on the issue.

In the meantime, striking workers who returned to the picket line Tuesday said refusing the latest offer was a matter of safety and quality of life.

"You leave your home at 5:30 in the morning so you don't see your kids when they wake up in the morning, and you go back to work from two to 7:30 at night so you're not there for the meal or homework," said Haddad.

He said the city's two latest contract offers are basically the same and would compromise the family life of bus drivers.

"There are tweaks here and there, but they're the same offer where our operators will not have a family life."

The union says it also wants Ottawa residents to know it wasn't the side that broke off the latest round of talks.

"When we went back to the table a second time, we were ready. The union was ready to negotiate through the holidays, while the city told us they were ready to negotiate only until Dec. 24 at noon," Haddad said.

The mayor, however, maintains the city has done all it can to reach a settlement.

"We truly believe we have done everything possible to come to a settlement and resolution of this dispute, when we come to an agreement, they walk away and bring up another obstacle," O'Brien told reporters on Monday.

"We've quite frankly gone as far as we can, which is why we reached out on Christmas Eve, sent a letter to Minister Ambrose asking her to force a vote on this strike settlement."

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

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

Even if the strike is settled soon, all buses will stay parked for five to six days while mechanics service the vehicles.

Negotiations between the two sides broke off Christmas Eve. No new talks are planned.

With a report from CTV Ottawa's Vanessa Lee