The looming Sept. 30 expiration of the federal offshore drilling ban has Republicans eyeing a high-stakes showdown on their favorite issue a month before the elections.

In the face of soaring gas prices and growing support among the public for expanded oil drilling, Speaker Nancy Pelosi (D-Calif.) and Senate Majority Leader Harry Reid (D-Nev.) have strenuously avoided votes on opening more land and sea for exploration.

But Congress would have to vote affirmatively to keep the offshore drilling ban in place, with the provision likely to be included in a continuing resolution to keep the government running through the elections and into next year.

The GOP will try to amend the CR to drop the ban, but if Democrats block them as expected, Republicans will again blame Democrats for stopping domestic energy production.

And some Republicans want to up the ante dramatically.

Some conservatives and drilling advocates want President Bush to threaten to veto any CR that extends the offshore drilling ban, which could spark a government shutdown.

“If [Bush] picks a fight and conservatives pick a fight, Democrats will have to explain why they want to shut down the government because they are so dedicated to keeping gas prices high, keeping oil in the ground and keeping us addicted to foreign oil,” said Ed Frank, vice president of public affairs at the conservative group Americans for Prosperity.

Frank, who worked in the Bush administration and as a GOP Hill aide, argues a veto would dramatically raise the profile on one of the few issues where polls show the public is on the side of conservatives.

Republicans could argue that “Democrats are trying to shut down this government because they are trying to keep us reliant on oil from Hugo Chavez and keep the price of gasoline high,” Frank said.

Christin Baker, a spokeswoman for White House Office of Management and Budget Director Jim Nussle, said the president’s action to lift the executive drilling ban puts more pressure on Democrats.

“At this stage, though, we’re just strongly urging the Democratic Congress to do the work they were elected to do in this term,” Baker said. “We’ll deal with Oct. 1 when it arrives. Until then, they should get busy.”

The conservative Republican Study Committee leadership is drafting a letter to the Democratic leadership insisting that any CR allow the offshore drilling ban to expire, but the RSC has not yet urged a Bush veto.

“Will the Democrat Congress actively extend the ban on deep sea drilling or will they begin supporting policies that increase American energy supply?” RSC spokesman Brad Dayspring asked.

The last government shutdowns in 1995 and 1996 were generally seen as disastrous for the then-new Republican majority. But on this issue, Frank said, the public is clearly on Republicans’ side.

“Seventy-five percent of the American people agree with us on this,” he said, adding that it will come down to whether Republicans have the gumption to make a stand. “If they don’t have the courage to force a showdown on this, I don’t know when they will.”

Any shutdown would presumably force the Democratic Congress to stay in town to resolve the crisis when they would rather be home campaigning, putting enormous pressure on lawmakers to reach a deal.

But a Democratic leadership aide said Republican incumbents are in far more danger this year than Democrats and will be the most eager to be campaigning. The aide also dismissed talk of a veto.

“I just do not think it is realistic that a lame-duck president is going to shut down the government over this issue,” the aide said. “That’s wishful thinking on somebody’s part.”

The ramifications of a government shutdown — stalled checks and the like — would quickly overwhelm the drilling issue, the aide said. “They are going to be more pissed about that than the price at the pump.”

Democrats have already signaled that they have no intention of moving any appropriations bills before the Sept. 30 end of the fiscal year with the exception of the Defense spending bill. That strategy allows them to postpone offshore drilling votes, which are usually held on a long-standing rider to the Interior bill.

Republicans said that their presumed presidential nominee Sen. John McCain (Ariz.) may not want to have such a high-profile role for an unpopular Bush so close to the election but that he may want to gamble on the strategy if he continues to lag in polls.

“When you get closer to election day, McCain may need a Hail Mary,” one pro-drilling GOP strategist said. “If we’re going to go for a Hail Mary with 30 days to go, why not do it with something that is one of the most pressing issues in the eyes of the American people in recent memory? … If the president is worth his salt on his way out the door he won’t sign any bill that does continue the ban.”

Democrats aimed a counterattack at Republicans, arguing they are beholden to the oil and gas industry and are blocking efforts to increase production on already leased land.

“The most interesting thing about Sept. 30 is that it is another campaign finance filing deadline, and therefore another opportunity for the American people to see the real reason why John McCain and Congressional Republicans suddenly support offshore drilling instead of forcing oil companies to drill on the land they already hold leases to,” said Sarah Feinberg, spokeswoman for House Democratic Caucus Chairman Rahm Emanuel (Ill.). “John McCain has already received $1 million in campaign cash from oil companies — how much will he and the Republican leadership have received by Sept. 30?”

Another House Democratic leadership aide predicted that their strategy would depend increasingly on what presumptive Democratic nominee Sen. Barack Obama (Ill.) wants to do, noting that Obama leads McCain in the polls on economic issues.