Republican senators held back on Monday from saying whether they would be willing to subpoena former National Security Adviser John Bolton, instead alternately advocating for making that decision after the upcoming impeachment trial’s opening phases or accusing House Democrats of presenting an incomplete case against President Trump.

As they returned to Washington Monday evening, many Republicans spoke to the press for the first time since Bolton announced Monday morning he’d be willing to testify if subpoenaed by the Senate. Multiple senators shifted to blame House Democrats for allegedly failing to include the former national security adviser’s testimony in their case.

“I don’t want to do their work,” Sen. Thom Tillis (R-NC) told reporters on Capitol Hill. “It’s not that I don’t want to hear form him, I want to hear from him when the House is willing to do their work.”

The House declined to subpoena Bolton for his testimony in November, after the longtime hawk and former U.N. ambassador’s attorney signaled Bolton wouldn’t comply with such a subpoena until a court ordered that he do so.

Sen. John Barrasso (R-WY) described House Democrats as “desperate,” saying that they did a poor job “of establishing a credible case.” Sen. Josh Hawley (R-MO) echoed that line, criticizing the House’s impeachment inquiry as “slapdash” while saying that House Democrats “were rushing to get to a result.”

“I don’t know why we would hear from him when he’s not included in any of the material, any of the case thats been made by the House Democrats,” Hawley said.

To Sen. Marco Rubio (R-FL), Bolton’s willingness to testify was also the fault of House Democrats.

“If the House thinks there’s additional testimony and so forth then they can take the item up again separately from what they’ve already done,” Rubio said.

Other Republicans — including the few who Democrats hope could vote with them on trial procedural issues — deferred to the position laid out by Senate Majority Leader Mitch McConnell (R-KY): that decisions on witnesses should wait until after the beginning phases of the trial, once each side presents its initial case.

Echoing McConnell, Sen. Susan Collins (R-ME) pointed to the Clinton impeachment, where witnesses were voted on after the preliminary phases.

Sens. Rick Scott (R-FL) and Mike Rounds (R-ND) also punted on commenting on subpoenaing Bolton by bringing up their desire to make that decision later on.

“I think we make up our minds on who we want for witnesses after we’ve heard from the House in terms of what their argument is,” Rounds said.

Sen. Pat Roberts (R-KS) managed to take both tacks, asking TPM, “shouldn’t we determine the process first?”

He added that the Senate’s job “isn’t to reopen witnesses and stuff that we haven’t even discussed.”

The timing of President Trump’s impeachment trial remains unknown, with Republican senators saying that Speaker of the House Rep. Nancy Pelosi (D-CA) has yet to transmit the articles of impeachment to their chamber. That, Senate GOPers say, prevents them from being able to schedule a start date to the trial over President Trump’s efforts to pressure the Ukrainian government for political dirt and alleged obstruction of Congress.