House Democrats signaled Thursday they will use subpoenas to require absent Republicans’ attendance in the Capitol, four days into a political standoff that has shuttered the Legislature.

In a meeting of the House Rules Committee, Democrats voted 4-0 to authorize the committee’s chair, Rep. Paul Holvey, D-Eugene, to subpoena the 21 Republicans lawmakers.

“I hereby require you to appear before the House Rules Committee at 1 p.m. on Thursday, March 5,” a copy of the document reads, adding that Republicans should be “prepared to testify about your unexcused absences during the 2020 regular session of the Legislative Assembly.”

Under state law, people who fail to abide such subpoenas can be compelled by a judge’s order. It is not clear whether that applies to lawmakers, who are not subject to some civil processes during legislative session.

The surprise strategy, not announced ahead of time, comes after Democrats telegraphed that they had limited options for forcing absent Republicans back to the Capitol. In a choreographed dialogue on the House floor Thursday morning, Holvey and House Speaker Tina Kotek discussed the ongoing boycott, and what they could do to compel Republicans to return.

Kotek and Holvey mentioned sending state police to retrieve the lawmakers, and freezing their staffing and supplies budgets. They made no mention of subpoenas.

House Republicans walked away from the Capitol on Tuesday, in order to block Democrats from passing climate change legislation this session. Senate Republicans had fled the building a day earlier, after the bill, Senate Bill 1530, advanced toward a vote in the Senate.