The NRCC recently reserved an additional $5.7 million for TV ads in six House races this fall — on top of the $18.2 million already announced, several sources told POLITICO. Still, the committee is playing catch-up with its Democratic counterpart: Even after the latest ad reservation, the NRCC will trail the Democratic Congressional Campaign Committee by a nearly 2-to-1 margin in reserved ad spending.

Picking up the tab for the NRCC’s ad push will be none other than GOP lawmakers looking to keep their majority.

The NRCC plans to jump-start its internal fundraising campaign Tuesday to extract $26 million from House Republicans — a major effort internally dubbed the Battleground Program.

Texas Rep. Jeb Hensarling, the No. 4 House Republican, is heading up the effort, which will be the subject of a closed-door meeting of lawmakers at the Capitol Hill Club on Tuesday, according to Republican aides.

The NRCC will also announce Tuesday that it raised $6 million last month — the committee’s best May since 2005. It has $33.8 million on hand. Democrats will announce their total Wednesday.

GOP leadership is trying to send a message to its members that the party is in good shape financially but that lawmakers need to pony up if they want to keep the majority. House Speaker John Boehner (R-Ohio) has tried to instill this sense of urgency in Republicans, warning them against resting on their laurels.

Illinois Rep. Peter Roskam, Majority Whip Kevin McCarthy of California and Hensarling are expected to cut big checks Tuesday to goad their colleagues into donating, according to an aide. They expect to raise $3 million at Tuesday’s meeting alone and another $3 million in the next few weeks, covering the $5.7 million in fresh reservations.

The DCCC has already reserved $46.1 million for ads in 60 districts in the fall, according to a Democratic source. The money will be used to challenge 37 Republicans, aid 11 Democrats and contest 12 open seats.

A majority of the new NRCC buys are in districts where Democrats have reserved ad time already. Republican strategists say they plan to continue escalating the air war as their fundraising allows.

The NRCC’s ad-buying apparatus has three objectives in this second round of buys: to help freshmen in Michigan, Ohio, New Jersey and Pennsylvania; boost veteran incumbents facing tough races in San Diego and Des Moines; and go on offense in Georgia.

The most notable new investment targets Georgia Democratic Rep. John Barrow. The NRCC is reserving $900,000 in the Augusta and Savannah media markets, a huge sum in those parts that will pay for two-plus months of ads.

Barrow, the last white Democrat in Congress from the Deep South, is part of the endangered breed of Blue Dog Coalition. Redistricting made his district redder, and President Barack Obama could be a top-of-the-ticket anchor that weighs him down.

The move against Barrow is a fresh reminder that Democrats need to pick up more than just 25 House seats to regain the majority, because they are likely to lose some incumbents. Despite winning the special election last week to replace former Democratic Rep. Gabrielle Giffords in Arizona, current conventional wisdom holds that Democrats are unlikely to win back the chamber.

Many of the reservations are in presidential swing states, where it will be harder and more expensive to reserve airtime in the fall as campaigns compete for coveted time slots. The flood of outside money facilitated by the Supreme Court’s Citizens United v. Federal Election Commission decision — from House Majority PAC on the left to the Congressional Leadership Fund on the right — guarantees the airwaves will be saturated in the final sprint to Election Day.

To be sure, committees are free to cancel, add to or otherwise adjust their reservations later. But the reservations send an important message about the party’s priorities.

The Battleground Program is the party’s major dues drive of the year. Lawmakers are assessed from $80,000 to $600,000 depending on seniority and committee assignments. Reps. Patrick McHenry of North Carolina, Kristi Noem of South Dakota, Lynn Westmoreland of Georgia, John Kline of Minnesota and Roskam are co-chairing the effort.

In addition to Barrow, the biggest buy is $1.7 million in the San Diego area on behalf of Rep. Brian Bilbray. He is facing former San Diego city councilman Scott Peters, a deep-pocketed self-funder who is part of the DCCC’s Red to Blue program.

The GOP has a slight registration advantage in a heavily redrawn district, but this month’s crowded primary suggested that he could be vulnerable. Bilbray took only 41 percent of the vote.

A close second is the $1.6 million Republicans are investing in the Philadelphia media market. Republicans have several potentially vulnerable members in the metropolitan area, including New Jersey Rep. Jon Runyan and Pennsylvania Rep. Mike Fitzpatrick. The DCCC has reserved $2.7 million for the market. Neither side knows yet which members they will focus their advertisements on after Labor Day.

The NRCC is protecting freshman Michigan Rep. Dan Benishek in his rematch against former state Rep. Gary McDowell in the Upper Peninsula seat long held by former Rep. Bart Stupak, a moderate Democrat. The NRCC is surpassing the DCCC’s buy, putting $533,560 into the Traverse City market and $258,000 into Marquette.

The party is spending nearly a half-million on behalf of Iowa Rep. Tom Latham, who is facing Democratic Rep. Leonard Boswell. In Ohio, Republicans nearly matched the DCCC by reserving $312,000 in airtime for the Youngstown market. Freshman Rep. Bill Johnson, who holds a northeast Ohio district in coal country that could be pivotal to deciding the outcome of the presidential race, faces a rematch with former Democratic Rep. Charlie Wilson. But the Democrats also purchased about $681,000 in ad time for the Charleston-Huntington, W.Va., and Wheeling-Steubenville markets.