National Rifle Association CEO Wayne LaPierre accused Michael Bloomberg of trying to "buy America" by spending $12 million on a gun control ad campaign.
"He can't spend enough of his $27 billion to try to impose his will on the American Public. ... And he can't buy America," LaPierre, an outspoken critic of the New York Mayor, said on NBC's Meet the Press on Sunday.
The New York Mayor is personally bankrolling an ad blitz to encourage senators to support increased background checks as part of a package of gun control reforms.
When Senators return from their holiday break they'll be taking up a new bill that will require background checks for every new gun purchase.
Background checks are currently only required if buying a gun from a licensed dealer with gun shows and private sales exempted.
LaPierre said he does not support requiring more background checks for gun buyers because "It doesn't work. Nobody gets prosecuted; it's completely ineffective."
"We have people all over, millions of people, sending us 5, 10, 15, 20 dollar checks telling us to stand up to this guy that says that we can only have three bullets, which is what he said. Stand up to this guy that says ridiculous things like, 'The NRA wants firearms with nukes on them.' I mean it's insane the stuff he says," LaPierre said.