Ahead of his testimony before Congress on Tuesday, a dozen House Democrats called for the U.S. ambassador to the European Union to resign over his role in the ever-evolving Ukraine scandal.

NBC News surveyed all 235 House Democrats. The majority said they would make a decision after the ambassador, Gordon Sondland, is deposed before the House committees conducting the impeachment inquiry on Tuesday.

The Democrats who called for Sondland’s resignation ahead of his testimony include: Reps. Gerry Connolly (VA), Lloyd Doggett (TX), Benny Johnson (MS), Denny Heck (WA), Filemon Vela (TX), David Price (NC), Bonnie Watson Coleman (NJ), Anthony Brown (MD), Dwight Evans (PA), Julia Brownley (CA) and Gwen Moore (WI). Several others, including Reps. Jan Schakowsky (IL) and Yvette Clarke (NY) indicated they were leaning toward pushing for Sondland’s resignation.

Sondland, a Trump-appointee, is set to testify on Tuesday following the release of a trove of text messages last week that revealed Sondland was an active participant in Trump and his attorney Rudy Giuliani’s efforts to pressure Ukraine into investigating former Vice President Joe Biden. In texts, Sondland and another U.S. diplomat who testified last week, made Ukrainian President Volodymyr Zelensky’s willingness to probe Biden a condition for an official White House visit with Trump.

Read TPM’s preview of Sondland’s testimony here.