Vice President Joe Biden and Senate Minority Leader Mitch McConnell have hashed out the broad outlines of a potential “fiscal cliff” deal that McConnell will discuss with Republican Senators at 2 p.m. this afternoon, according to a GOP source.

The source cautioned that the talks are ongoing and explained that that in the meeting, McConnell would update his caucus on the details of his discussions with Biden, seeking input from them. The last McConnell-Biden phone call took place at 6:30 a.m.

Without commenting on the specifics of the emerging agreement, the source described it as trading “permanent Republican priorities in exchange for temporary Democratic priorities.”

Both the Politico and the Washington Post have reported that the agreement would extend current tax rates for income under $400,000 for individuals and $450,000 for families. Assuming those were permanent, it would mean enshrining the bulk of the Bush era tax cuts.

It’s expected that any deal would also address the estate tax, the alternative minimum tax and dividend income on the revenue side; and unemployment insurance as well as Medicare physician payments on the spending side. Another tricky issue is what to do about the automatic “sequester” cuts scheduled to start going into effect on Jan. 1. The spending issues could get delayed a few months and become part of another showdown over raising the debt limit.

If a deal can be struck that has sufficient Republican and Democratic support in the Senate, it would still need to pass muster with the House before any actual legislation moves forward. Even if a deal is reached, it’s unclear whether any sort of compromise could be formally voted on today, or if it would spill over until tomorrow. By that point, the nation would have technically gone over the cliff already, though financial markets would be closed for New Year’s Day.