(Updates with issue involving natural-gas vehicles.) By Siobhan Hughes Of DOW JONES NEWSWIRES WASHINGTON (Dow Jones)--U.S. Senate Democrats proposed eliminating the cap on damage claims that companies must pay for oil spills like the one in the Gulf of Mexico, vowing to ensure that companies responsible for spills will cover "100 percent" of damages, according to a draft summary of the measure released Tuesday. But the summary from Senate Majority Leader Harry Reid (D., Nev.) was short on details, leaving open key questions such as how the Senate would raise money to pay for initiatives such as one to encourage more natural-gas vehicles and suggesting Democrats may not be ready to vote on spill legislation this week. "Time is pretty short," Sen. Byron Dorgan (D., N.D.) told reporters after Senate Democrats finished a weekly caucus meeting. He said he expects the Senate to vote on the bill "between now and a week from Friday." Democratic leaders in the U.S. House of Representatives have already circulated their own legislation, which is scheduled for a vote Friday. Under the bill, Congress would discard the cap on liability limits and would ban BP PLC (BP, BP.LN) from bidding on new leases for as many as seven years. -By Siobhan Hughes, Dow Jones Newswires; (202) 862-6654; siobhan.hughes@dowjones.com (END) Dow Jones Newswires July 27, 2010 16:02 ET (20:02 GMT)