ST. PAUL — Minnesota’s Democratic Party asked an administrative judge Thursday to rule that a veteran Republican lawmaker broke the law with letters to newspapers that say four Democrats had voted for billions in new taxes.

The party’s complaint against Rep. Greg Davids of Preston was filed with the Office of Administrative Hearings. It claims Davids was conflating routine procedural votes as support for the substance of legislation. Before a bill approved in one committee can be heard by the next, a committee report is adopted by the full House. That step is increasingly resulting in recorded votes.

One letter printed in the Tribune on Feb. 25, under the headline, “Savick favors anti-business tax.” He described how state Rep. Shannon Savick voted in a Feb. 20 procedural vote. It quickly drew response letters.

The complaint is something of a pre-emptive strike aimed at heading off use of the votes in campaign materials in 2014.

It argues that Davids violated a law against false political claims by writing letters to the editor in districts of four Democrats who barely won their races. The letters seized on a motion to advance the committee report on Gov. Mark Dayton’s tax bill and portrayed the vote as endorsing $3.7 billion in new taxes.

Davids said he is confident in his interpretation of the votes, citing a passage in a procedural guidebook often consulted by the Legislature.

“I am the test case,” he said.

On that, the sides agree. The Democratic complaint warns that letting the tactic go unchecked would “effectively paralyze the Minnesota House” by forcing more debate and roll call votes on motions that aren’t meant to get into the substance of bills in question.