If the Capitol seems quiet this week, maybe it’s because lobbyists are holding their breath as they await action on the emergency supplemental spending bill.

Lobbyists and lawmakers are wondering whether a veto from President Bush will require Congress to strip domestic spending from the post-veto version of a measure that topped $123 billion in each chamber. Bush has threatened to reject the bill (HR 1591) if it contains Iraq withdrawal provisions or too much spending for items he considers unnecessary.

Until a veto, professional advocates say, there is not much point in making appeals — at least not to appropriators.

“Pray,” Julian B. Heron, counsel and lobbyist for the Western Growers Association, tells his clients. “Pray hard.”

If money is cut from the supplemental after an expected veto, the intended recipients might need divine intervention to get it back. Because the “emergency” accounts are not subject to discretionary spending caps, the supplemental may be the best chance for lawmakers to fund pressing domestic priorities without blowing a hole in the budget or slashing other programs.

The House and Senate versions contain billions of dollars above the president’s initial request, for non-defense, non-security domestic accounts, including Gulf Coast hurricane recovery, children’s health insurance, energy assistance for the poor, Western wildfire suppression and disaster assistance to producers of crops such as California avocados and Georgia peanuts.

If aid for food producers is stripped from the supplemental, Heron said, “The farmers are still going to need their help and need it badly.”

For now, many lobbyists are waiting.

“There isn’t a whole lot that we can do right now because appropriators still have to come up with the conference report before they can start over again,” said an advocate for Gulf Coast funding.

The House’s $74 million line item for peanut storage has been a frequent target of criticism by the White House and others.

Robert L. Redding Jr., a lobbyist for the Georgia Peanut Commission, said he has spent a lot of time talking to members and staff about the program, which pays for peanut storage under a federal marketing assistance loan program. Redding would not say whether publicity has made the program vulnerable to being struck if appropriators are forced to pare domestic spending after a veto.

“We just hope we can keep it,” he said.

Mark Wolfe, executive director of the National Energy Assistance Directors’ Association, said he hopes bipartisan support in Congress will help protect hundreds of millions of dollars for the Low Income Home Energy Assistance Program (LIHEAP).

But he conceded that “LIHEAP is clearly in play” as the process moves forward.

“I can’t imagine the president would hold up the whole bill over LIHEAP,’’ he said. “But then again, who knows?”

Wolfe was not the only lobbyist to point his finger at Bush or congressional Republicans. Tom Buis, president of the National Farmers Union (NFU), said GOP leaders had blocked agriculture disaster funding at Bush’s behest in the 109th Congress.

House Speaker Nancy Pelosi, D-Calif., told the NFU’s annual convention in March that the supplemental would include farm funding.

“Without a doubt, it was the [GOP] leadership that kept it from happening,” Buis said. “There’s new leadership now.”

Group members visited Capitol Hill the week before the recess. Some have been meeting with lawmakers and aides during the break to press their case for keeping the money in place, Buis said.

Another battle taking shape is over federal chemical-security regulations. Both House and Senate versions of the supplemental spending bill would bar the Homeland Security Department from issuing regulations that pre-empt stronger state and local chemical-security regulations.

The fiscal 2007 Homeland Security appropriations bill (PL 109-295) gives the Homeland Security secretary authority to regulate chemical plants but does not guarantee state and local governments the power to enforce stronger regulations.

Although the chemical industry has lobbied lawmakers to drop the new security provisions, groups such as the National Environmental Trust and the American Association of Justice, formerly the Association of Trial Lawyers of America, say they have succeeded in preserving them so far.

“Our allies tell us they would have the votes to keep it in conference,” said Andy Igrejas, environmental health program director at the National Environmental Trust.

But Igrejas said the veto threat has the environmental lobby looking at a future supplemental. Although George V. Voinovich, R-Ohio, dropped plans to try to strike the chemical-security language on the Senate floor, he could try again if it is included in a second supplemental spending bill.

New Jersey lawmakers have campaigned to keep the chemical-security provisions in the supplemental because they are concerned that recently issued Homeland Security Department regulations could pre-empt future expansion of New Jersey’s already tough regulations.

An aide to Frank R. Lautenberg, D-N.J., who pushed the provisions in the Senate, said Lautenberg is focused on keeping them strong in conference but would look for other appropriations bills to attach them to if the supplemental is vetoed.

“If he chooses to veto, we look for another way to get this done,” the aide said, adding that possible vehicles would not be limited to a supplemental spending bill.

Patrick Yoest contributed to this story.