WASHINGTON — In its last session before crucial midterm elections, Congress is expected to generate much heat — but little light — on issues of concern to U.S. Jews.

Much of the legislative rush in the 19 working days between Labor Day and the early October return home to campaign will be consumed with posturing ahead of elections that could change the leadership in one or both houses.

There will be last-minute efforts to outlaw assistance to the Palestinian Authority and enhance Iran’s isolation, as well as initiatives to control the flow of reconstruction aid to Lebanon.

The American Israel Public Affairs Committee is lined up behind those initiatives, AIPAC spokeswoman Jennifer Cannata said.

“AIPAC is pursuing a robust fall agenda that includes action to impede Iran’s pursuit of nuclear weapons, further isolate the terrorist-led Palestinian Authority and support the full implementation of the U.N. cease-fire agreement in Lebanon,” she said.

Domestically, Congress is deadlocked on immigration reform and appropriations for homeland security.

Insiders say the outlook for all these initiatives is dim — and their sponsors know it. The idea is to get the rhetoric in place in time for the final blitz of campaign ads.

The key issue will be who is better placed to protect Americans.

“It’s all about national security,” a senior Democratic aide said, reviewing the schedule.

Democrats plan to make an issue out of what they say is thin protection at the nation’s ports and the assignment of homeland security funding, which they say lopsidedly favors interior states that vote Republican.

Republicans will try to regain their traditional lead on security issues, saying Democrats are likelier to appease terrorists.

“Five years after our nation was attacked, the terrorist danger remains,” President Bush said Tuesday in the second of a series of speeches he is giving on terrorism. The White House hopes the speeches will bolster the Republicans’ precarious chance of keeping both houses.

One substantive light amid the rhetorical din on homeland security is movement on $25 million allocated annually for nonprofits.

Most of the 2005 funds were allocated to Jewish groups seeking protection at synagogues, schools and community centers. Until this summer, the Homeland Security Department had held up allocation of the 2006 funds, saying it preferred to save them for actual instead of potential threats.

Following meetings among Jewish lobbyists, department officials and the staff of the relevant Senate appropriations subcommittee, however, officials now say they expect the department to disburse the 2006 funds and both houses of Congress to agree to appropriate $25 million for 2007.

“We have had very productive conversations with the Department of Homeland Security,” said William Daroff, vice president for public policy of the United Jewish Communities, the federations umbrella that, together with the Orthodox Union, has led lobbying for the funds. “We are in a pretty upbeat position with legislative and administration support. Now it’s a matter of getting through the endgame.”

Republicans will once again consider new measures to stymie illegal immigration, something that Jewish groups that deal with immigration have opposed.

On the foreign front, Rep. Ileana Ros-Lehtinen, R-Fla., chairwoman of the U.S. House of Representatives’ subcommittee on the Middle East, is sponsoring two bills that are high on the pro-Israel lobby’s agenda.

Ros-Lehtinen’s Iran Freedom Act would broaden punitive and criminal sanctions against Iran to include third parties overseas that deal with the Islamic republic, and the Palestinian Anti-Terrorism Act would cut off the Palestinian Authority until its Hamas government is removed and the authority commits to far-reaching anti-terrorism steps.

Neither act is expected to pass this session, principally because of administration opposition to stringent provisions in both bills that inhibit the president’s prerogative to execute foreign policy. In both cases, the Senate — traditionally friendlier to administration prerogatives — is holding up the tougher elements of the bill.

A pro-Israel lobbyist who favors both bills says passage is not the only measure of their effectiveness. Ros-Lehtinen’s bills got overwhelming support in the House, the lobbyist said, strengthening Bush’s hand in dealing with the Palestinians and Iran.

As a result, the lobbyist said, isolating Iran and containing its nuclear program has evolved since last year from a U.S.-Israel issue to an international issue. The U.N. Security Council is set to consider sanctions against Iran now that the Islamic republic has rejected calls to stop enriching uranium, which most countries believe is for nuclear weapons, despite Iranian denials.

“The community has been effective at pushing Iran to the forefront,” the lobbyist said. “The administration has the backing it needs to move forward at the United Nations.”

Rep. Tom Lantos, D-Calif., threatened over the summer break to use his prerogative as ranking member of the House International Relations Committee to put a hold on any funds headed for Lebanon unless that country allows international troops to patrol its border with Syria.

Such a deployment would hinder weapons running to Hezbollah but is unlikely to happen, even though it was written into the U.N. Security Council resolution that ended the 34-day war between Israel and Hezbollah this summer. Syria has said it would view the presence of foreign soldiers on its border as a hostile act.

Lantos is unlikely to press the issue further, insiders said, because of the administration’s determination to get assistance to Lebanon at a time when Hezbollah is already on the ground currying favor by handing out cash from its Iranian backers. Israel has called for the swift disbursement of Western funds to counter Hezbollah’s pork-barrel politicking.

The defense appropriations bill — and the $2.5 billion that goes to Israel — might also be a temporary victim of the posturing over homeland security, insiders said. If that happens, Congress will rush through the appropriations in December, when it meets for a final lame-duck session.

Here too, however, the aftermath of the Lebanon war may play a role. Sen. Dianne Feinstein, D-Calif., who is Jewish and known for her unstinting support of Israel, has quietly introduced an amendment to the defense appropriations bill mandating that any funds for cluster bombs must come with guarantees that the weapons will not be used in areas populated by civilians.

The amendment does not name a country, but it clearly addresses human-rights group reports that Israel used the U.S.-made weapons in civilian areas in Lebanon, a charge Israel has vigorously denied.