Republican outside groups are using "fiscal cliff" negotiations to put pressure on vulnerable Democrats up for reelection in 2014.

A $240,000 radio ad campaign is targeting Sens. Mark Begich (D-Alaska), Kay Hagan (D-N.C.), Tim Johnson (D-S.D.), Mary Landrieu (D-La.) and Jay Rockefeller (D-W.Va.). 

President Obama's proposal will create "massive tax increases" and "even more debt," according to the ad. The senators are asked to "give us a balanced plan."

The group has already gone up with a $500,000 cable television campaign pushing for Obama to offer a plan with lower taxes and less spending. 

The American Action Network, another Republican-backed outside group, is up with a small buy of Web ads saying Obama needs to "get serious" about the fiscal cliff.

Meanwhile, the White House is pushing its own outside game, asking supporters to submit stories of what $2,000 -- the tax increase for the average middle-class family should we go over the cliff -- means to them.

"If you take the time to share your story, you're going to get the attention of a White House staffer," senior adviser David Plouffe wrote in an e-mail. "That's the bottom line - someone is going to take time to listen." 

On Monday, Obama deputy campaign manager Stephanie Cutter asked the president's backers to call House Republicans and urge them to pass an extension of the Bush tax cuts for incomes under $250,000. The Obama campaign arm used a similar strategy in the health-care debate, getting volunteers to make hundreds of thousands of phone calls to Congress.