Ahead of another round of high-stakes deficit talks at the White House, Senate Republican leader Mitch McConnell announced this afternoon a Republican "back up" plan for raising the debt ceiling if the White House talks fail - a plan he described as a "last choice" option.

The plan is complicated, but essentially the president would have the authority to raise the debt ceiling in three increments until the 2012 election without having to agree to spending cuts upfront. He would only have to submit proposals for spending cuts with each request to raise the debt ceiling.

McConnell said the plan is not his first choice, but Republicans wanted to send a signal to the markets that there is a way out.

"We think it’s extremely important that the country reassure the markets that default is not an option," McConnell said in announcing his plan.

McConnell admitted that this legislation does not guarantee the spending cuts the Republicans have been fighting for, but there may be no other way to avoid default.

"We have become increasingly pessimistic that we will be able to reach an agreement with the only person in America who can sign something into law, and that's the president of the United States,” McConnell told reporters.

More details on the plan per two GOP aides:

Congress would write a law that requires the president to submit to Congress a request to raise the debt ceiling three separate times before the 2012 election, totaling $2.4 trillion dollars to cover the government's obligations.

Part one: The initial legislation would authorize the president to submit a request to Congress asking to increase the debt limit by $700 billion and would require submission of a plan to reduce spending by a commensurate amount.

Once Congress receives that request, the debt limit would be provisionally increased by $100 billion to avoid an Aug. 2nd default.

The $700 billion request would also would trigger a so-called "resolution of disapproval" in Congress. Congress would then vote on that resolution. The assumption is that House Republicans would vote in favor of the resolution to voice their protest over the debt ceiling increase and Senate Republicans are betting they could get enough Democrats to vote for the resolution. If both chambers pass the resolution to disapprove of the debt-ceiling increase, McConnell said he assumes the president would veto it, and that veto would be sustained in Congress, because only one-third plus one would be needed. Hence the debt ceiling is increased.

Parts two and three: This same process would be repeated in the Fall of 2011 and the Summer of 2012 -- both times at a $900 billion increase.