Lawmakers are still working to reach a final agreement on a new comprehensive energy bill. Republican leaders had hoped to wrap up the talks last week and to send the first major overhaul of the nation’s energy strategy in a generation back to the House and Senate this week, but negotiators disagreed over a handful of issues. These issues include a proposed tax credit for a planned $20 billion natural gas pipeline from Alaska, which would transport natural gas from Alaska’s North Slope down to the lower 48 states.

Members were also debating a liability provision that would shield makers of the gasoline additive methyl tertiary-butyl ether (MTBE) from some lawsuits. MTBE, which refiners add to gasoline to make fuels burn more cleanly, has been blamed for water contamination in a number of states.

Democrats, led by Sen. Barbara Boxer, D-Calif., circulated a letter objecting to the liability protection for MTBE producer and garnered 43 signatures. Only 40 votes are needed to stop a bill.