Senate Republicans on the Environment and Public Works Committee saythey may block panel Democrats from holding a mark-up hearing to passclimate legislation.

Matt Dempsey, the committee's minority spokesman, said Republicans want more time to study the bill and for the Environmental Protection Agency to perform a more thorough review of the bill's costs.

EPA did release an initial look at the legislation last Friday when Democrats also unveiled the Senate climate measure, co-sponsored by Sens. John Kerry of Massachusetts and Barbara Boxer of California.

It projected only modest cost increases from the bill, but the assessment was partly based on a previous review of the climate bill passed by the House.

Democrats...