(CNN) - Despite a new bipartisan push on climate change, legislation on the issue is unlikely to make it to the Senate floor this year, two Senate Democratic sources tell CNN.
That would be a blow to three senior senators set to unveil a much anticipated bipartisan measure dealing with climate change Monday morning.
The main reason sources say the prospects for the legislation are dim is because Senate Democratic leaders have decided to try to put immigration reform first on the agenda, and after that there likely won't be an appetite for another politically divisive issue before November's election – especially with a Supreme Court nomination ahead and a desire to stay focused on the politically potent issue of jobs.
The Democratic sources said the feeling in the Senate Democratic leadership is that immigration has more of a political upside for Democrats for several reasons.
Democrats know that Latinos who voted for President Obama and other Democrats in 2008 are furious that Democrats have not yet kept the promise to advance comprehensive immigration reform.
Immigration is especially critical politically for Senate Majority Leader Harry Reid, D-Nevada, who is down in the polls for his re-election bid in a state where a quarter of the population is Hispanic.
On Monday, Sen. John Kerry, D-Massachusetts, Sen. Joe Lieberman, I-Connecticut, and Senator Lindsey Graham, R-South Carolina, are slated to release legislation that would, among other things, set a goal of a 17 percent reduction in carbon emissions in the next 10 years.
A Kerry spokeswoman downplayed any talk of not moving on the issue before November.
"There are always people who think it's impossible to tackle big challenges in an election year, but Senators Kerry, Graham, and Lieberman have been working overtime to produce an approach that can succeed," said Kerry spokeswoman Whitney Smith.
"The majority leader reiterated yesterday to them that he is committed to make this the year bi-partisan, comprehensive climate and energy reform passes the Senate and Senator Kerry knows the leader is tough and determined enough to make it happen."