[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/images/10/12/art.graham.gi.jpg caption="Graham has decided to abandon talks with Democrats on climate change legislation."]
(CNN) - In a stunning move that could throw a major roadblock in front of two of President Obama's biggest legislative initiatives, Sen. Lindsey Graham abruptly declared Saturday he's abandoning talks on climate change legislation because he believes Democratic efforts to bring up a separate immigration reform package is undermining the legislative process.
"Moving forward on immigration - in this hurried, panicked manner - is nothing more than a cynical political ploy," the South Carolina Republican wrote in a sharply-worded letter obtained by CNN.
The letter was sent to business, religious, and conservation leaders that the senator has been working with on the climate change legislation. An aide to Graham told CNN the senator will no longer be attending a major news conference scheduled for Monday with Democratic Sen. John Kerry of Massachusetts and independent Sen. Joe Lieberman of Connecticut to unveil details of their "tri-partisan" climate change legislation.
Graham is the only leading Republican who has been working with the White House on the contentious issue.
A senior White House official told CNN that in recent days Graham has been privately threatening that he would abandon the climate talks unless Senate Majority Leader Harry Reid, D-Nevada, backed off of plans to push forward with comprehensive immigration reform ahead of the environmental legislation.
Reid released a statement Saturday saying he’s still committed to tackling both issues and will not be deterred by Graham’s decision.
“I appreciate the work of Senator Graham on both of these issues and understand the tremendous pressure he is under from members of his own party not to work with us on either measure,” said Reid. “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."
An aide said Graham was involved in a "flurry" of talks in the last 48 hours with Kerry and Lieberman and in those conversations nobody disabused the Republican of - as CNN reported Friday – the fact that Senate Democrats have changed course and will now move immigration ahead of climate change on the legislative calendar in the coming weeks. CNN reported Friday that climate change is now unlikely to even make it to the Senate floor at all this year.
Graham's decision to release the letter allowed the private negotiations to spill into the public, and administration officials acknowledge it now could be much harder for Obama to get bipartisan consensus on both issues that are key to his agenda.
In his letter, Graham blasted the Democratic plans to move immigration reform ahead of climate change legislation: "Let's be clear, a phony, political effort on immigration today accomplishes nothing but making it exponentially more difficult to address in a serious, comprehensive manner in the future”
"Unless their plan substantially changes this weekend, I will be unable to move forward on energy independence legislation at this time. I will not allow our hard work to be rolled out in a manner that has no chance of success,” he added.
But a senior Democratic source involved in the climate change talks fired back that "the only thing 'phony' here is Lindsay Graham" because he's pulling out amid pressure from fellow Republicans to block Obama's agenda.
This is also an about-face on immigration reform for Graham because he has been pressing the White House to move forward on comprehensive reform on that issue as well. His move comes just one day after Obama called on both parties to pass immigration reform on the federal level in response to a new law in Arizona that will allow local police to stop individuals suspected of being illegal immigrants.
Democrats privately charged Saturday that Graham was trying to scuttle immigration reform in order to protect his close friend, Sen. John McCain, R-Arizona, from having to deal with a sticky issue in advance of his tough August GOP primary battle in Arizona to keep his Senate seat. McCain has previously pushed for comprehensive immigration reform but has been recently talking about securing America's borders first, a position that puts the senator more in line with his conservative primary opponent, former Rep. J.D. Hayworth.
But Graham spokesman Kevin Bishop told CNN those allegations are "nonsense." He said Graham's letter has nothing to do with McCain and everything to do with the fact that Senate Democrats are talking about a quick three-week window to try and push through immigration reform.
"Senator Graham worked on immigration for many months in 2007 with virtually every senator and two cabinet secretaries," said Bishop. "It was an unprecedented effort and it is what it takes to put together a comprehensive plan. A serious immigration plan cannot be put together in three weeks."