Two moderate Senate Democrats who jointly opposed the unlimited liability language in the chamber's oil-response bill today unveiled separate "compromise" proposals.

Sens. Mark Begich (D-Alaska) and Mary Landrieu (D-La.) -- vocal critics of the unlimited liability language in Senate Majority Leader Harry Reid's (D-Nev.) energy and oil spill-response package (S. 3663) unveiled last week -- introduced separate measures that they say will hold oil companies accountable, without placing a burden on taxpayers and without shutting out smaller companies from operating offshore.

The oil-state Democrats have been some of the staunchest critics of Sen. Robert Menendez's (D-N.J.) language in Reid's bill that would eliminate the current $75 million liability cap for companies involved in a spill. Doing so, Begich and Landrieu say, would exclude all but the largest energy companies from operating offshore.

Democrats blamed Republicans for blocking efforts to pass the energy and oil spill-response package this week, but members of their own party -- namely Begich and Landrieu -- said they too had serious concerns with provisions in the bill and refused to support it.

But after standing firm on the issue all week and promising to offer up compromise language that both Democrats and Republicans could support, Begich and Landrieu are floating separate proposals.

The proposals are similar in principle but vary in the details.

Begich's proposal, which he released as a discussion draft this morning, would require companies to carry a minimum liability of $250 million. After that, operators would collectively share liability for up to $20 billion in damages. And if the economic damages from a spill exceeded the $20 billion mark, the liability would fall back on the individual company, which could be required to set up an independent escrow account.

Landrieu's measure comes as part of a larger oil spill-response package (S. 3763) that she introduced last night. It mirrors a proposal she began discussing last week that also raises the initial cap to $250 million. After that, a $10 billion mutual insurance fund fed by industry would kick in. And if economic damages associated with the spill maxed out that fund, payment responsibility would return to the company responsible for the spill with no limit on liability.

Aides for the two senators said they are continuing to work together on the issue. A spokeswoman for Begich said the senators decided to offer up separate proposals after failing to compromise on minor differences.

"Everyone just got to the end of the day ... and wanted to get those ideas laid out on the table," the spokeswoman said.

Begich said he is offering up his liability language as a separate proposal from other energy or oil spill-response legislation, although he plans to float a separate measure that deals with revenue sharing.

"I'm trying to keep them separate so we can get to agreement on one, so we can move to the next," Begich said yesterday. "And revenue sharing will be the next one I'll move to."

But Landrieu has stressed she would oppose any bill that does not bring relief to Gulf states.

"I ask that you support our effort to ensure that any legislation addressing this oil spill also establishes a dedicated stream of revenue that will assist the impacted states in recovering from this unprecedented disaster," Landrieu wrote in a letter yesterday to Senate leaders.

Her measure (S. 3763), which she originally introduced in May, also includes provisions to lift the Obama administration's moratorium on deepwater drilling and speed up revenue-sharing with coastal states, among other provisions.

"Any oil spill legislation that the Senate considers must bring justice to Gulf Coast residents, businesses and communities who have been devastated by this oil disaster," Landrieu said. "If Congress wants to make good on the promise to make the Gulf Coast stronger than it was before the spill, it starts with getting the offshore oil and gas industry up and running and directing a robust stream of funds to saving our coast."

Reid has indicated he is open to considering alternative liability language in the energy and oil spill-response package that he has promised to bring back to the floor in September. But Begich has said he would also be willing to move his bill as a stand-alone measure if that is the best option.

Click here to read the letter from Landrieu to Senate leaders.