(CNN) The Senate Leadership Fund, a super PAC affiliated with Senate Majority Leader Mitch McConnell, is overseeing the Peachtree PAC, a new political action committee that emerged in recent days to shape the US Senate runoffs in Georgia, officials tell CNN.
The group will spend $43 million in new television and radio ad spending. That's on top of the roughly $80 million that the McConnell-aligned political organization already has committed to spend through the Senate Leadership Fund and American Crossroads, another super PAC.
"The fate of our country hangs in the balance in Georgia," Senate Leadership Fund President Steven Law said in a statement to CNN. "This new activity through Peachtree PAC will articulate the stakes couldn't be higher as the future of freedom is on the ballot."
His statement came after CNN inquired about the Peachtree PAC and its shared media buyer with the Senate Leadership Fund.
Peachtree will begin its advertising blitz Wednesday, reservations show.
The January 5 runoffs -- pitting Republican Sens. Kelly Loeffler and David Perdue against Democrats challengers Raphael Warnock and Jon Ossoff -- will determine whether Republicans retain their Senate majority next year.
The twin races have drawn staggering sums already: Television and advertising spending had approached $400 million as of Tuesday, according to the latest data from Kantar's Campaign Media Analysis group. So far, Republicans lead Democrats in spending by about $242.4 million to $154.3 million.
The tally includes spending since November 10 and reservations through the January 5 runoffs.
Peachtree's burst of activity reflects the rise of pop-up super PACs, political action committees with local-sounding names that emerge to influence individual contests without making clear to voters their ties to national groups or the sources of their funding.
A national Democratic super PAC, the Senate Majority PAC, launched two super PACs active in the Georgia contests: The Georgia Way and Georgia Honor. Together, those two groups have spent about $17 million in the runoffs, according to Kantar data.
Using misleading super PAC names allows national party interests to "launder the money and launder the message" in local races, said Brendan Fischer of the nonpartisan Campaign Legal Center.
The surge in activity by the Peachtree PAC already has made it one of the top spenders in Georgia.
The Peachtree PAC filed its statement of organization with the Federal Election Commission on November 6 -- as the two runoffs came into focus.