A majority of the D.C. Council on Tuesday signed on to  legislation that would rein in a political action committee run by allies of Mayor Muriel E. Bowser.

Council members said a flood of more than $300,000 in contributions to the group in recent months, mostly by businesses seeking contracts with the city, threatened to corrupt a District government still reeling from an ongoing federal investigation into the last mayoral administration.

“Just what are we becoming here, Tammany Hall?” asked D.C. Council member Mary M. Cheh (D-Ward 3), who introduced the measure with David A. Grosso (I-At Large).

The legislation would close a loophole in city election law that allows a PAC to accept contributions of unlimited size during years in which the group is not actively working to elect a candidate. Ben Soto, treasurer of the pro-Bowser PAC and the mayor’s former campaign treasurer, told The Washington Post last week that he was beginning a fundraising drive to fill the PAC’s bank account with $1 million by the end of the year.