Huge tax hikes and sweeping spending cuts are hours away from going into effect, unless lawmakers can reach a deal before tonight's midnight deadline.

As rank-and-file lawmakers return to Capitol Hill, they're hoping to have a fiscal cliff deal to vote on today.

However, according to the Associated Press, Senate Majority Leader Harry Reid and Senate Republican leader Mitch McConnell remain at odds on key issues like the income threshold for higher tax rates. The Kentucky Republican has reached out to Vice President Joe Biden, who has assumed the lead role for Democrats. Together, they're hoping to break the impasse.

“I’m frustrated by the fact that we still do not have an agreement to avoid the fiscal cliff," vented Rep. John Carney, D-Del. "A large, comprehensive plan has always been my goal -- but we’re running out of time for that kind of agreement. I’m hopeful that the negotiations currently happening between Vice President Biden and Senator McConnell will yield a fair plan that is as comprehensive as possible.”

The fiscal cliff is the combination of the expiring Bush-era tax cuts and mandatory across-the-board spending cuts; both kick in in 2013.