With the City Council still divided on whether and how to pay for a streetcar, Charlotte Mayor Anthony Foxx on Monday postponed a city budget workshop until Dec. 17.

The streetcar is the main sticking point in finding six votes, a council majority, to agree to a long-term capital spending plan for the city. Council members have already met twice this fall in an effort to reach a compromise, but have failed so far.

But in an email to council members sent Monday afternoon, Foxx seemed to raise the bar on how much support he expects any capital budget to have.

Rather than the typical majority of six votes, Foxx said a capital plan needs seven votes to move forward and be supported by the community.

“I see no reason to approve a capital plan with marginal council support and will not support any plan until seven or more of you come together to support something – with or without the streetcar,” Foxx wrote.

Thirty minutes before Monday’s 2 p.m. meeting was supposed to begin, the city sent out an email saying it had been rescheduled. The postponement surprised some council members and city staff, who were preparing for the workshop.

City Manager Curt Walton has proposed spending $119 million on a central Charlotte streetcar line. That is part of an overall $926 million long-range capital plan, which would be paid for with an 8 percent property tax increase.

That plan fell apart in June when Foxx vetoed a compromise budget by six members that was smaller and didn’t include the streetcar. The mayor then started budget talks in early fall, hoping to avoid another last-minute collapse in the spring.

The city will soon start construction on a 1.5-mile starter streetcar line from Presbyterian Hospital to Time Warner Cable Arena. Walton’s proposal would extend that line to Johnson C. Smith University and also along Hawthorne Lane to Central Avenue.

Five council members support paying for the streetcar with property taxes. Six council members are against that plan, though some are open to paying for the streetcar with property taxes along with other revenues, such as a special assessment of property owners along the line.

In his email, Foxx said the city faces a number of challenges, such as the so-called “fiscal cliff” in Washington D.C., and the controversy over Mecklenburg County’s property re-evaluation. Because of that, Foxx said the city’s capital plan needs the strong support of council members.

“Doing anything otherwise would undermine public confidence and put any resulting bond referendum at risk,” Foxx said.