A number of Senate and U.S. House of Representatives Democrats have sided with environmental groups against Reid's plan to allow additional offshore areas to be opened to oil exploration and drilling. Reid had hoped the proposal would insulate Senate Democratic Party candidates from public anger over rising gas prices, The Hill, a Washington newspaper, reported Tuesday.

Legislation drafted by Reid and Senate Energy and Natural Resources Committee Chairman Jeff Bingaman, D-N.M., would allow nearly 1 billion acres off the coast of Alaska to be explored for oil and would accelerate leasing opportunities in the Gulf of Mexico.

But Reid's plan has strong opposition.

"I am unalterably opposed to drilling," said Sen. Frank Lautenberg, D-N.J., a member of the

Environment and Public Works Committee, citing the recent Mississippi River oil spill.

House Speaker Nancy Pelosi, D-Calif., is also reportedly against the plan and may not allow it to be brought to the floor of that body. She told The Hill that lawmakers should focus on the National Petroleum Reserve on Alaska's North Slope instead of on offshore drilling.