The political power of San Francisco’s newly formed progressive majority on the Board of Supervisors is being tested by two issues under debate today: commuter shuttles and affordable housing requirements for new development.

The eventual outcomes will indicate how mighty is the progressive bloc when it comes to policy-making at City Hall. The political maneuvering also comes as progressives seek to retain their majority this November, when six of 11 seats on the Board of Supervisors are up for election.

The San Francisco Municipal Transportation Agency’s board of directors will vote today whether to amend its previously approved commuter shuttle program after the progressive bloc called for changes last week as part of a tentative deal.

Supervisor David Campos, who helped negotiate the deal, said he expects the SFMTA board to approve the changes. The approval would result in the dismissal of an environmental appeal of the program filed by SEIU 1021, a labor union with 6,000 members.

“The expectation is that it will pass,” Campos said.

That, however, won’t stop the more moderate Supervisor Scott Wiener from sending a letter today calling on the board of directors to stick with the “solid” program it had previously approved and not to cave into the “pressure.” Wiener said the changes move The City toward a “tear down” of the program. The shuttles transport thousands of tech workers to the South Bay for companies like Apple and Google.

Under the proposed changes, the shuttle program would extend for one year, using no more than 125 Muni stops, with a required review after six months. The City would also analyze only allowing shuttles to stop at “hubs,” such as at parking lots, rather than Muni stops.

If approved, a revised program incorporating those provisions would come before the SFMTA board for approval on March 1. A study would also be commissioned to analyze the impacts of commuter shuttles on housing costs and displacement.

Meanwhile, the progressive bloc is pushing The City to amend its affordable housing requirements for developers with a June charter amendment, introduced by supervisors Jane Kim and Aaron Peskin. The measure would remove the existing below-market-rate unit requirements from the City Charter and allow the board to amend the requirements through legislation. It would also impose an interim requirement of 25 percent of onsite units at below market rates, up from the current 12 percent mandate.

As the board is expected to vote Feb. 23 whether to place the charter on the June ballot, there is an ongoing debate over dueling June ballot measures related to its presumed passage — one submitted by Mayor Ed Lee and the other by Kim and Peskin. The mayor’s would require a financial study as part of a specific process for adjusting the current affordable unit requirements. The measure from Kim and Peskin would set 25 percent as the minimum below-market-rate requirement. The board’s Rules Committee will discuss both measures today.

As the mayor and developers have voiced concerns about the impacts of the 25 percent minimum, negotiations are ongoing. An agreement may be reached in which the dueling measures are dropped from the ballot and instead the board would approve legislation reflecting the compromise.

Kim said negotiations center on grandfathering developers in the planning process.

“The compromise is around what projects in the pipeline will be required to do the 25 percent,” Kim said. “We’re still figuring out what that sweet spot is.”

Peskin is part of the negotiations. “There is widespread sentiment that The City’s affordable housing requirements are too low and a widespread desire to increase them,” Peskin said, “and the devil is in the details.”

Since Peskin was elected to the board, Lee has had a tougher time imposing his political will at City Hall.

“I think for the first time in a number of years, we have a board that is playing its role of being an appropriate checks and balances,” Peskin said, adding that what results are better outcomes for every resident “rather than an elite few.”

Board of Supervisors Aaron PeskinCity HallCommuter Shuttle ProgramDavid CamposEric MarGoogle busJane KimJohn AvalosPoliticsProgressiveprogressive politicsSan FranciscoScott WienerSEIU 1021