Mayor de Blasio on Friday defended his opposition to using a taxpayer-financed defense fund for all immigrants facing deportation, saying those convicted of serious crimes already had their day in court and represent just a small fraction of the city’s undocumented population.

“I think this a very narrow and specific group,” said de Blasio on WYNC radio. “…We’re talking about dozens of people a year that fall under these categories, maybe a little more, verses 500,000 undocumented people, the vast majority who are law abiding and just want to get by.”

De Blasio opposes a controversial immigration measure that the City Council sneaked into the city’s new $85.2 billion budget that would allow undocumented immigrants convicted of serious crimes to taps a $26 million defense fund to block deportation.

De Blasio has said he’ll deal with the issue by adding restrictions that would bar dangerous offenders from getting the money.