State Rep. Mike Connolly. Photo courtesy of State House News Service / Sam Doran.

Progressive lawmakers, advocates and local officials gathered Wednesday to promote a bill they said would give cities and towns a new tool to fight the state’s housing crisis – an option to impose a new fee on certain real estate transactions.

Speakers unveiled what they described as “compromise” legislation, backed by the filers of three different local option transfer fee bills and home rule petitions for property transfer taxes in specific communities.

The bill would authorize municipalities to impose a fee between 0.5 percent and 2 percent on real estate transactions above the statewide median sale price for single family homes – currently $400,000 according to The Warren Group, publisher of Banker & Tradesman – and a fee of up to 6 percent for certain “speculative real estate transfers,” with proceeds going toward affordable housing in that municipality. None of the coalition’s bills state how the median price is to be calculated. No government entity tracks that data, although The Warren Group and the Massachusetts Association of Realtors regularly publish their separate calculations of that figure.

Rep. Mike Connolly, one of the backers, described the language as a set of “common principles” that lawmakers will use to try to find consensus among their colleagues. He said his “absolute goal” is to see it included in a broader housing bill that also includes measures like tenant protections.

“In my district, in Cambridge and Somerville, there are sites, there are properties, where the value has doubled, tripled, maybe even quadrupled, over a 10-year period and if an owner or a developer is seeing the value of their property skyrocket, I think most reasonable people don’t feel it’s too much to ask if we could just capture 2 percent or so of these massive transactions to dedicate to local affordable housing programs,” Connolly said during the press conference.

A roster of the measure’s backers include many prominent affordable housing developers and activist groups.

The proposal comes as lawmakers, backed by Boston Mayor Marty Walsh, are also weighing proposals to generate new revenue for transportation by allowing communities or regions to pass binding transportation project and financing proposals. However, real estate industry groups oppose transfer taxes, saying they will dampen investment and pass costs on to homebuyers.