Washington (CNN) - The battle for control of the Senate is getting even more interesting, thanks to a move by the National Republican Senatorial Committee to reserve nearly $3 million to pay for television commercials to run in the closing days of this year's midterm election campaigns in California, Washington, and Wisconsin.
The NRSC confirms that nearly $2 million will be spent in California alone, where poll suggest the battle between three-term Democratic Sen. Barbara Boxer and former Hewlett Packard CEO Carly Fiorina, the GOP challenger, is nearly deadlocked.
"Barbara Boxer's partisan and ineffective record has finally caught up with her, and we believe this is the year California turns the corner on its economy by electing a new leader in the Senate. We're preparing to go on offense and ensure Carly Fiorina has the resources she needs to win in November," NRSC Communications Director Brian Walsh tells CNN.
But Democrats are questioning the GOP move.
"Their whole pitch about Fiorina was that she's a self funder and they wouldn't need to spend any money. She's a multi-millionaire, so why are they pouring cash into her?" a Democratic source tells CNN.
The NRSC is also expected to spend just over half a million dollars in Washington and $470,000 in Wisconsin, two other states where they are hoping to win back Senate seats. Patty Murray of Washington and Russ Feingold, both three-term Democratic senators who have large campaign warchests, face competitive contests this year as they bid for re-election.
At the end of last month, the NRSC reported having $19.7 million cash on hand while the Democratic Senatorial Campaign Committee reported just over $21 million in the bank.
The Republicans currently control 41 seats in the Senate and need to win back 10 seats to take control of the chamber.
–Follow Paul Steinhauser on Twitter: @psteinhausercnn