The Bloomberg administration is going to oppose a bill that could put buyers of fake luxury products behind bars, The Post has learned.

The bill, first proposed two years ago by Councilwoman Margaret Chin (D-Manhattan), finally got a hearing yesterday.

In addition to jail time of up to a year, bargain hunters ready to buy a “Rolex” from a guy in an alley would face a $1,000 fine.

“It’s such a large fine it would deter people from making nearly any purchases,” said one source, explaining the administration’s opposition.

Images of wide-eyed tourists being hauled off by cops wouldn’t sit well with City Hall, either.

But Chin argued that drastic measures are necessary because the counterfeit trade continues to thrive in Chinatown, which she represents, despite repeated raids.

“What we’re trying to do is cut down on the demand,” she said.

Chin scoffed at the idea that some naive buyers might not realize they’re engaging in a criminal transaction.

“If you’re buying something off the street, paying cash, doing it in a sneaky way, c’mon,” she said.

Councilman Peter Vallone Jr. (D-Queens) said he has a problem with the jail-time provision, but is ready to impose a less severe penalty.

“I would absolutely consider making it a violation,” he said, noting that other countries such as France and Italy already impose large fines.

“You don’t have unknowing buyers any more,” said Vallone, mentioning that transactions often involve shady characters in back alleys. “It’s more like a hostage exchange.”