WASHINGTON — In a move that may derail a comprehensive climate change and energy bill in the Senate, one of the measure’s central architects, Senator Lindsey Graham, has issued an angry protest over what he says are Democratic plans to give priority to a debate over immigration policy.
Mr. Graham, Republican of South Carolina, said in a sharply worded letter on Saturday that he would no longer participate in negotiations on the energy bill, throwing its already cloudy prospects deeper into doubt. He had been working for months with Senators John Kerry, Democrat of Massachusetts, and Joseph I. Lieberman, independent of Connecticut, on the a legislation, which they were scheduled to announce with considerable fanfare on Monday morning. That announcement has been indefinitely postponed.
In his letter to his two colleagues, Mr. Graham said that he was troubled by reports that the Senate Democratic leader, Harry Reid of Nevada, and the White House were planning to take up an immigration measure before the energy bill. Mr. Graham has worked with Democrats in the past on immigration matters and was expected to be an important bridge to Republicans on that issue, as well as on energy.
Mr. Graham said that any Senate debate on the highly charged subject of illegal immigration would make it impossible to deal with the difficult issues involved in national energy and global warming policy.
He said in his letter that energy must come first and that Democrats appeared to be rushing to take up immigration because of rising anti-immigrant sentiment, including a harsh new measure signed into law in Arizona on Friday.
“Moving forward on immigration — in this hurried, panicked manner — is nothing more than a cynical political ploy,” Mr. Graham said. “I know from my own personal experience the tremendous amounts of time, energy and effort that must be devoted to this issue to make even limited progress.”
Hours after Mr. Graham released his letter, Mr. Kerry said in a statement that Mr. Graham’s actions had scuttled plans for an elaborate announcement of the proposal, whose passage is a major priority for the Obama administration.
“We all believe that this year is our best and perhaps last chance for Congress to pass a comprehensive approach,” Mr. Kerry said. “We believe that we had reached such an agreement and were excited to announce it on Monday, but regrettably external issues have arisen that force us to postpone only temporarily.”
Mr. Kerry said that he was prepared to resume work on the climate measure when Mr. Graham rejoined the discussion. But he said he was uncertain when that would be.
“We will continue to work, and we will do everything necessary to be ready when the moment presents itself,” Mr. Kerry said.
Progress on an energy and climate bill in the Senate has relied heavily on Mr. Graham’s active participation and support. He is the only Republican to have formally endorsed a broad approach to dealing with global warming and energy issues and is needed to try to bring in support from other Republicans.
Carol M. Browner, the White House coordinator for energy and climate policy, said that the administration would work to secure bipartisan agreement on both energy and immigration measures this year.
She praised Mr. Graham for his efforts to build a coalition of business and environmental organizations in favor of comprehensive energy legislation. “We’re determined to see it happen this year,” Ms. Browner said, “and we encourage the senators to continue their important work on behalf of the country and not walk away from the progress they’ve already made.”
Mr. Reid has spoken of the importance of dealing with immigration but has not definitively said that it would take precedence over energy and climate legislation. But he has said that the current system is broken and must be reformed.
Mr. Graham wrote that Mr. Reid’s refusal to state explicitly that energy would come first “has destroyed my confidence that there will be a serious commitment and focus to move energy legislation this year.”
He said that reducing the nation’s dependence on imported oil and reducing emissions of greenhouse gases were such contentious issues that they required the full commitment of the Senate and the White House. “All of the key players, particularly the Senate leadership, have to want this debate as much as we do,” Mr. Graham wrote. “This is clearly not the case.”
Mr. Reid said in a statement that he intended to work on both issues in this session of Congress. “As I have said, I am committed to trying to enact comprehensive clean energy legislation this session of Congress,” he said. “Doing so will require strong bipartisan support and energy could be next if it’s ready.”
He said that revising immigration law will also require bipartisan support and noted that significant committee work had not yet begun on the issue.
Mr. Reid said that Mr. Graham was under “tremendous pressure” from fellow Republicans not to cooperate with Democrats on either energy or immigration. In a swipe, he added, “But I will not allow him to play one issue off of another, and neither will the American people. They expect us to do both, and they will not accept the notion that trying to act on one is an excuse for not acting on the other.”