With Aaron Peskin's November election to the District 3 seat, the Board of Supervisors is set to make a shift to the left. However, what day he officially begins his job is ultimately up to Mayor Ed Lee, and with several important votes possibly coming before the Board the week of December 7th Lee may decide keep Peskin on the sidelines just a tad bit longer.

Replacing current D3 Supervisor Julie Christensen, Supervisor-elect Peskin is considered more progressive than and less cooperative with the mayor than Christensen — a difference that shifts the balance of Supervisors' power away from the Mayor's Office and the moderate bloc of the Board. As Mayor, Lee has the power to delay the start of Peskin's term by up to 10 days — an action that would maintain the moderate majority until after crucial votes are cast. Lee has this power as the Department of Elections certified election results don't take effect until approved by the Board in a vote, and then signed by Lee.

As The Examiner reports, this is a muscle that the mayor is not afraid to flex, having delayed signing certified election results by eight days on two separate occasions.

And what could be impacted by the mayor's timing? The Examiner points out that the future of both the potential Mission Bay Warriors arena and a new jail (with a possible price tag of $600 million according to Supervisor Jane Kim, but a pricetag of $380 million per the Ex) could be decided next week. The jail project is opposed by Kim and other progressives on the Board, and it is reasonable to assume that Peskin would vote with them to kill the project.

How likely is Mayor Lee to delay signing the certified election results? Supervisor John Avalos thinks we should expect it.

“No one expects the mayor to approve the will of the voters right away,” Avalos told the Examiner. “I expect more that he’s trying to rush the voting on legislation before Peskin gets sworn in."

Supervisor Scott Wiener seemed to suggest that the mayor will sign the election results when it suits him to do so, telling the Examiner that "[Lee] will sign it whenever he is ready to sign it," but refused to speculate on any possible motive for the potential timing.

“I know some people like to look for conspiracies," said Wiener. "There is no conspiracy here.”

What does Supervisor Peskin think about all of this? Well he's currently on vacation in Nepal and can't be reached for comment.

Related: Does San Francisco Need A New Jail?