WASHINGTON - As Senate Democrats tried Friday to pass a $60 billion bill for Sandy relief and beat back Republican amendments, New Jersey was missing one vote: Sen. Frank J. Lautenberg's.

The Democrat has not yet returned to Washington after the Senate's Christmas break, leaving Democrats with just a 52-47 edge. Working in their favor is that any amendment to the bill requires 60 votes.

"Sen. Lautenberg is at home recovering from the flu, and the Capitol physician advised him to continue resting and not return to the Capitol to vote unless absolutely necessary," said Lautenberg spokesman Caley Gray.

Lautenberg has missed votes on four of the last five days on which the Senate had roll call votes. He took part in a Dec. 21 cloture vote on the Sandy relief bill, helping it clear a key procedural hurdle.

Lautenberg turns 89 in January. Missing key votes for health reasons could give more fuel to comments from some quarters that he should not run for reelection in 2014.

The senator was also not visible following the shootings in Newtown, Conn. Lautenberg made no public speeches or appearances, despite having long advocated for tougher gun laws. His statements on the issue were limited to press releases.