WASHINGTON — The U.S. Congress’ recent preoccupation with Israel’s war in Lebanon could abort what had been this year’s signature victory for some pro-Israel lobbyists: the Palestinian Anti-Terrorism Act.

JTA has learned that congressional staffers are in a last-minute rush to reconcile divergences in different versions of a bill that aims to severely restrict assistance to the Palestinians. The Senate version, favored by the White House, is considerably less restrictive.

The principal factor burying what had been an overwhelmingly popular bill in both houses has been a last-minute pre-midterm elections flood of lawmaking, including resolutions relating to Lebanon.

“The problem is that we were interrupted by Lebanon,” a U.S. House of Representatives staffer who is involved in the negotiations and whose boss supports the House legislation told JTA last week. “Otherwise we would be further along.”

Other factors taking up congressional time in recent weeks included an abortive effort to reverse presidential policy banning embryonic stem-cell research; a failed effort to pass a constitutional amendment banning gay marriage; the Iraq war; immigration issues; and debate over the minimum wage.

But it is specifically the Lebanon issue that has preoccupied the same staffers whose job it was to reconcile the U.S. Senate version of the anti-terror act, passed in June, and the House version, passed in May.

Lawmakers in both houses tinkered for a week in mid-July with a resolution supporting Israel in its war against Hezbollah in Lebanon, while addressing concerns that both sides protect civilian lives. And now that those resolutions have passed, both houses are considering resolutions that call for a ceasefire.

Lawmakers who backed the act said that if anything, the events in Lebanon made it even more urgent to get a version of the bill to Bush for a signature.

“I think the whole advent of this two-front war Israel is engaging in has created a greater sense of urgency for passage,” Rep. Robert Wexler, D-Fla., said July 26 from Israel, where he was on a solidarity tour. “I think there’s a growing awareness in both houses that that needs to be accomplished.”

Procedure would have each house consider and then vote on the other’s bill; then both bills would go to a conference of lawmakers from the Senate and the House.

It’s too late for the House to consider the Senate’s bill, because the House launched its August break last Friday. The Senate is convening for another week, however, and staffers from both bodies hope to get a Senate vote on the House version this week, allowing at least one bill to go to conference.

Both houses could then have a quick vote on a conferenced version in September, when Congress reconvenes for its last five weeks.

The concern is that leaving the pre-conference negotiations until September — with just five weeks of work before Congress breaks up for elections — will probably kill the bill for this session of Congress.

The congressional staffer, who spoke on condition of anonymity because the bill is still in negotiations, was confident that the bill could clear hurdles and reach a Senate vote by the end of this week.

“I don’t see a real problem,” the staffer said. “There’s a difference between the two versions, but they’re not unbridgeable.”

Rep. Ileana Ros-Lehtinen, R-Fla., the chairwoman of the House Middle East subcommittee who sponsored the House version of the bill, is known to be leading efforts to get her bill to the Senate floor.

Both bills ensue from January’s electoral victory by Hamas, a terrorist group that does not recognize Israel. Each conditions U.S. assistance to the Palestinian Authority on renouncing terrorism, abiding by existing agreements and recognizing Israel.

But the differences are substantial. The Senate bill, for instance, focuses restrictions on a “Hamas-led Palestinian Authority” while the House bill focuses generally on the Palestinian Authority. Mahmoud Abbas, the relatively moderate P.A. president elected separately, is believed to be machinating the ouster of Hamas and its replacement with moderates.

Should he succeed, the Senate version would immediately be moot, while the House’s stringent restrictions would still be in place and could hinder any Bush administration efforts to prop up the moderates.

Additionally, the Senate bill allows broader funding for Abbas’ security requirements, which would help bolster him should Hamas challenge his authority; imposes fewer reporting requirements on the president, should he waive any of the bill’s provisions; and is much less restrictive on aid transferred to non-governmental organizations.

The American Israel Public Affairs Committee, which pushed both bills strongly, said the main thing now was passage of one or the other.

“Congress has repeatedly made it clear that no American taxpayer money should go to support a terrorist-run government and recent events only further underscore that fundamental point,” said Jennifer Cannata, AIPAC’s spokeswoman. “Hamas, like its similarly Iranian-sponsored cousin Hezbollah, remains committed to a violent, terrorist agenda that rejects Israel’s right to exist and undermines America’s policies in pursuit of peace in the Middle East.”

The bills split the Jewish community. On one side, a coalition of three smaller, dovish pro-Israel groups defied AIPAC and opposed the more restrictive House version. They were joined by the Reform movement, which threw its weight behind the more moderate Senate version. On the other side, the Orthodox Union pressed for increased restrictions in both bills.

Brit Tzedek v’Shalom, a group that organized grass-roots Jewish opposition to the House version, now argues that the bills are outdated.

Instead, Steve Masters, the national chairman of Brit Tzedek’s advocacy and public policy committee, said it was time to an accelerate an end to fighting in the Gaza Strip, which escalated after June 25 when Hamas-affiliated gunmen killed two Israeli soldiers in a cross-border raid and abducted another, Cpl. Gilad Shalit.

“The issue confronting the United States, Israel and the world community is how do we negotiate a cease-fire in Gaza that will return Gilad Shalit, stop the Kassam rockets from falling into southern Israel and restore the Gaza Strip into a state of affairs where basic services and life can continue to go on,” Masters said.