London is moving closer to a labour disruption by the city's inside workers, but last chance negotiations between management and CUPE Local 101 continue.

Closed door talks began Thursday morning in an effort to reach a new collective agreement.

A strike or lockout deadline is set for 12:01 a.m. Saturday, giving the two sides just one more full day before either finding an agreement or watching picket lines go up.

The 750 inside workers represented by CUPE Local 101 perform a wide range of municipal services including social services, business licencing, building inspections and bylaw enforcement.

The threat of a labour disruption is proving to be London's mostly rookie council's first major challenge.

Mayor Matt Brown was unanimously endorsed as the mayoral candidate of choice by the London and District Labour Council just last September and at the time he was described as having "the ability to work collaboratively to move a positive agenda" and "restore a respectful climate at city hall."

But heading into talks the union called on its members to take part in an email campaign directed at the mayor, deputy mayors and city manager.

It says in part "It is time you showed respect for the workers who help build this community with a fair contract offer without any concessions."

Other councillors who also received a labour council endorsement now find themselves walking a political tightrope.

Councillor Mo Salih says, "I think it was understood that they felt I was a candidate willing to listen, and that's been consistent - I listen to all Londoners."

"I think a lot of the decisions we make as a council are difficult," says Councillor Tanya Park. "There's a lot of things we have to balance, like city priorities versus big vision priorities and I see this as nothing different."

Talks are expected to continue through Thursday evening and resume on Friday morning if no agreement is reached.