The Democratic National Committee (DNC) is suing the Federal Election Commission for the second time in five months to force the agency to move on a complaint against Sen. John McCain ’s presidential campaign as soon as possible.

The DNC requested an FEC investigation in February of the Arizona Republican’s decision to withdraw from the federal matching fund system during the primary race. The legality of the McCain move was questioned by FEC Chairman David Mason at the time, but because the agency lacked a quorum no action was taken.

An earlier DNC lawsuit to compel the FEC to pursue the matter was rejected when a district court ruled the agency had 120 days to act. That deadline has expired, prompting the renewed pressure from the DNC.

The FEC still can’t take action, however, until the Senate approves five pending commission nominees, something that may happen before Congress recesses for the Fourth of July.