A bill that the City Council passed to make government more accountable will be a useful weapon for those who advocate releasing teachers’ ratings to the public.

That’s what Mayor Bloomberg said today as he signed the bill into law at City Hall. The law, sponsored by 21 council members and Public Advocate Bill de Blasio, requires the city to make incrementally more data available each year until 2018, when all city data will have to be posted to a single online warehouse and made available to researchers and members of the public.

The bill became law just days after the Department of Education released individual teachers’ ratings to news organizations that had filed legal requests for them. The release caused widespread condemnation, including from some of the elected officials who supported the bill, such as de Blasio. State officials are reportedly weighing how to shield new evaluations from also becoming public.

But Bloomberg has steadfastly stood by the release, and today he said the new law would stack the deck in favor of future releases, too.

“I think this bill and the fact that the City Council passed it will be used as evidence in any teacher litigation where people try to stop us from giving parents data about their children and the performance of the people who are serving them,” he said.

Bloomberg’s full comments about the Teacher Data Reports are below.

It will also be very useful in fighting back those who don’t want data out there. Sometimes people don’t want to look at what the data says or believe what the data says.

And it’s the public’s data and particularly you saw, I think last week, that parents have a right to know whatever data that we have in the Department of Education and it’s the parents that have to make decisions on their children.

And I think this bill and the fact that the City Council passed it will be used as evidence in any teacher litigation where people try to stop us from giving parents data about their children and the performance of the people who are serving them.

(The video was taken by Philip Ashlock, who works on open government issues for OpenPlans, which was consulted in the drafting of the bill. GothamSchools is a project of OpenPlans.)