Democratic Sen. Maria Cantwell, who is a leader in the fight against revived GOP efforts to allow oil exploration in the Arctic National Wildlife Refuge (ANWR), said modest oil prices could deter development, but cannot replace a federal drilling ban. "I just worry that that's the security of last resort," she said when asked whether oil markets could thwart development even if restrictions are lifted. "I don't think they are going there," she added.

Why it matters: Cantwell's comments come amid questions about how much oil companies will be willing to spend money on Arctic exploration if prices remain modest and amid opportunities for lower cost production in the lower-48 states.

Cantwell, the top Democrat on the Energy and Natural Resources Committee, spoke ahead of a hearing this morning in her committee on ANWR drilling. She criticized the GOP proposal to raise revenues from leasing in the region, saying Republicans need money in order to "give a tax break to millionaires."

Republicans are using the budget process to enable legislation to open ANWR to drilling that's not subject to Senate filibusters. Cantwell warned against policies she said could "destroy" the refuge.

Yes, but: Oil industry officials have long maintained they can develop the coastal plain of the refuge with a minimal environmental footprint.

What's next: Cantwell refused to concede that Republicans definitely have enough votes, despite the failure of her floor amendment last month to strip provisions from the budget resolution that pave the way for drilling legislation.

• "We have talked to some [Republicans] who voted that way who said, 'oh, I didn't really consider your amendment the final vote on that,' so we will have to see," she said of the 52-48 defeat of the amendment last month.