It appears unlikely that a bill to give the Food and Drug Administration power to regulate tobacco products will make it through Congress before the elections.

The bill’s lead GOP sponsor, Sen. John Cornyn of Texas, asked whether the bill would see action before members left to campaign said, “Realistically, I don’t think so.”

Aides to key Democratic lawmakers also acknowledged that the bill, passed by the House 326-102 on July 30, was unlikely to clear the Senate, given its crowded calendar.

“While Senator Reid supports this legislation, we have many issues to address in the coming weeks,” said Regan Lachapelle, spokeswoman for Senate Majority Leader Harry Reid , D-Nev.

The legislation has been a priority for Sen. Edward M. Kennedy , D-Mass., who sponsored a companion Senate bill, but he has been sidelined by surgery for a malignant brain tumor and will not be back in the Senate before January. “His not being able to be here has created more challenges,” Cornyn said.

Kennedy spokeswoman Melissa Wagoner, when asked to list Kennedy’s priorities for the end of the year, did not name the tobacco legislation. Asked why, she said “it depends on floor time” — something Democrats have in short supply during the next several weeks.

“It’s a crowded calendar,” Cornyn said.

The bill would give the FDA power to regulate tobacco products, and introduce strict new advertising, labeling and marketing rules.