SALEM, Ore. (AP) — Republican state senators in Oregon who boycotted the Legislature for a record six weeks earlier this year have filed a federal lawsuit as part of their efforts to seek reelection despite a recent voter-approved measure aimed at preventing walkouts.

The senators are challenging an amendment to the state constitution approved by voters last year that bars lawmakers from reelection if they have 10 or more unexcused absences. The measure passed by a wide margin following GOP walkouts in the Legislature in 2019, 2020 and 2021. Confusion over its wording has sparked a debate over what the consequences of this year’s walkout would be for boycotting senators.

Three Republican state senators, along with three county Republican central committees and two voters, filed the lawsuit in the U.S. District Court of Oregon on Monday. In the complaint, Sens. Dennis Linthicum, Brian Boquist and Cedric Hayden — who all racked up more than 10 unexcused absences during this year’s walkout — argue that expressing their political views through protest is protected under the First Amendment of the U.S. Constitution and shouldn’t disqualify them from reelection.

In the complaint, the lawmakers described walkouts as a tool the minority party could use to protest against the policies of Democrats, who hold majorities in both chambers of the Legislature.

The lawmakers also allege the measure violates their 14th Amendment right to due process.

This year’s GOP walkout sought to block Democratic legislation on abortion, transgender health care and guns. It prevented the state Senate from reaching the two-thirds quorum it needed to conduct business and held up hundreds of bills for six weeks.

The defendants named in the lawsuit are Secretary of State LaVonne Griffin-Valade and Democratic Senate President Rob Wagner. Wagner declined to comment on the suit, and Griffin-Valade’s office didn’t immediately respond to an emailed request for comment.

Several Oregon state senators with at least 10 absences have already filed candidacy papers with election authorities, even though Griffin-Valade announced in August that they were disqualified from running for legislative seats in the 2024 election.

Under Measure 113, lawmakers with more than 10 unexcused absences are supposed to be disqualified from being reelected for the following term. Some Republicans have raised questions over the measure’s vague wording.

The constitutional amendment says a lawmaker is not allowed to run “for the term following the election after the member’s current term is completed.” Since a senator’s term ends in January and elections are held in November, Republican state senators argue the penalty doesn’t take effect immediately, but instead after they’ve served another term.

The federal lawsuit comes on top of a state lawsuit filed by Republican state senators that is set to be heard by the Oregon Supreme Court next month.