Mayor Marty Walsh defended his decision to veto a Boston City Council effort to implement lobbying reform, even after vowing to write those transparency measures into law.

In a letter submitted to City Council members Thursday, Walsh vetoed a proposed ordinance that would have been the city’s first-ever regulations requiring lobbying disclosure.

Walsh told WGBH News the City Council’s ordinance, passed two weeks ago, was “too weak,” and he proposed his own. Walsh’s reforms come as a home rule petition, which means the state legislature would have to approve it, and its passage is not certain.

“The bill that came to me from the council didn’t have the right tools in it to really make it enforceable, and it exempted a lot of pieces. ... Their law didn’t have any teeth in it,” Walsh said during an interview with Boston Public Radio Friday. “If we’re truly going to talk about transparency, transparent is: let’s get a lobbying law in the books that’s a real law, that can work hard.”

Walsh says he is confident his version, which includes higher fines for noncompliance and a broad exemption for lobbying expenditures of $2,500 or less, will pass.

To hear Mayor Walsh’s full interview with Boston Public Radio, click on the audio player above.