(CNN) -- A spokesman for Sen. Harry Reid dismissed as "meritless" an ethics complaint filed Wednesday by Republicans that charges the majority leader improperly used his government-funded website and Twitter account for partisan political purposes.
At issue are Reid's ongoing attacks against Charles and David Koch, the billionaire brothers who are spending millions through their organization Americans for Prosperity to defeat Democratic candidates this campaign cycle.
Some of Reid's comments, which he has made in speeches on the Senate floor and elsewhere, also appeared on his senate.gov website and on his official Twitter account.
"Senate rules are clear: Senators and their staffs are prohibited from using official resources for partisan, electoral activities," said the complaint filed by Roger Villere, the chairman of the Republican Party of Louisiana.
"Senate staff receive publicly funded salaries for the performance of official duties and no campaign or electoral activities should take place on Senate time, or using official Senate equipment or facilities."
"Republicans' blind obedience to the shadowy billionaire Koch brothers is on full display today," Reid spokesman Adam Jentleson said in a statement.
"Nothing says 'Republicans are the party of the top one percent' like lashing out with meritless complaints as a screen to defend the Koch brothers as they rig the system to benefit billionaires like themselves. Sen. Reid will continue to do everything in his power to hold the Koch brothers and their Republican enablers accountable for trying to tilt the playing field in favor of the wealthy and against the middle class."
Congressional ethics experts contacted by CNN were divided over whether Reid's actions violated ethics rules.
"Some of this material could be viewed as technically running afoul of the rule," said George Washington University law professor Jonathan Turley.
"The problem is that the rule covers legislative matters that are inherently political. Most things posted or tweeted by members are done so with some partisan or political purpose. Moreover, criticism the Koch brothers is akin to criticisms of other public figures or organizations that are the focus of public officials from those producing violent video games to corporate welfare complaints."