WASHINGTON (AP) – Republicans will work into the weekend in hopes that Congress will be able to wrap up a $40 billion-plus spending cut plan, though a fight over oil drilling in Alaska remains an obstacle.

The defense budget and the largest of the government’s domestic appropriations bills remain unfinished as well.

The end-of-session chaos was dominated by a bid by Sen. Ted Stevens, R-Alaska, to attach a plan for Arctic National Wildlife Refuge drilling to a massive defense spending bill for the current year. That legislation blends Pentagon funding and money for the war in Iraq with hurricane relief aid and a scaled-down plan to fight avian flu.

At the same time, a $602 billion appropriations bill for the departments of Labor, Health and Human Services, and Education has stalled in the Senate because GOP moderates dislike funding levels for many programs. GOP leaders are considering adding that measure to the ever-growing defense bill.

It remained unclear whether Stevens would succeed in his 25-year quest to open a wildlife refuge along Alaska’s North Coast to drilling. The cantankerous Alaskan said he is “pretty close” to getting the votes required to overcome a procedural challenge planned by opponents of drilling in ANWR.

Democrats – who said Stevens was flouting the Senate’s rules and traditions in trying to attach the drilling plan to the must-pass defense budget – are mounting a fierce drive in opposition, but they also acknowledged they won’t mount a full-blown filibuster.

“We’re pulling out all the stops with our people because this is outrageous,” said a senior aide to Minority Leader Harry Reid, D-Nev.

The chaos reigned as critical details on the longer-term budget plan – a key piece of the GOP’s fall agenda – remained to be worked out.

The bill would take on, for the first time since 1987, the spiraling growth of federal benefit programs such as Medicaid, Medicare and student loan subsidies. It is part of a campaign by Republican leaders to burnish their party’s budget-cutting credentials as they try to reduce a deficit swelled by spending on the Iraq war and Hurricane Katrina.

House Budget Committee Chairman Jim Nussle, R-Iowa, said he is hopeful that official House-Senate talks expected Saturday would produce agreement on the budget plan.

Vice President Dick Cheney came to the Capitol to wheedle lawmakers in an attempt to win White House priorities such as killing a program that compensates companies hurt by trading partners who “dump” their exports in this country.

The bill is modest compared with previous efforts, but it has nonetheless set off a political firestorm on Capitol Hill and among activists for the poor. Tentative agreements include:

-Raising $3 billion by increasing the per-employee premiums paid into federal pension guaranty funds from $19 to $30.

-Saving $13 billion from the student loan program, in part by establishing a fixed 6.8 percent interest rate instead of maintaining lower variable rates.

-Saving about $6 billion from Medicaid by requiring new co-payments for prescription drugs, tightening rules designed to limit the ability of elderly people to shed assets to qualify for nursing home care, and increasing rebates paid by drug manufacturers.

-Freezing Medicare physician payments for one year instead of allowing a 4.4 percent cut to be imposed. A so-called “pay for performance plan” to link health care provider payments to the quality of care they give their patients was under consideration to help offset the $7 billion cost of forestalling the cut to doctor fees.

-Cutting a net of $3 billion from agriculture programs, mixing $4 billion in cuts with an extension of a milk income payment program that benefits smaller dairy farms. House Agriculture Chairman Robert Goodlatte, R-Va., reluctantly dropped a plan to end eligibility for about 250,000 food stamp recipients.

Disagreements remained over a White House-backed plan to save $3.2 billion over five years by killing a program championed by Sen. Robert C. Byrd, D-W.Va., that diverts to U.S. companies the duties paid to the Treasury by trading parties that “dump” their exports at below-cost prices. Many Senate Republicans, including Mike DeWine of Ohio and Larry Craig of Idaho, strongly oppose the idea.

The House and Senate are at loggerheads over Senate-passed provisions providing additional grant aid to low- and middle-income college students. Senate Health, Education, Labor and Pensions Chairman Mike Enzi, R-Wyo., is strongly resisting House attempts to slash a $14 billion package of grant program increases.

Separately, the House and Senate Appropriations Committees negotiated over an enhanced aid package for Gulf Coast hurricane victims and a scaled-back response to President Bush’s $7.1 billion request to combat avian flu. The avian flu plan was likely to be limited to the $4 billion that Bush requested for the ongoing fiscal year.