Five more Republican representatives may join Ken Buck in resigning from the House of Representatives if they continue to be dissatisfied with the party’s nominee for the presidential election, Donald Trump.

On Tuesday, Buck, a Colorado congressman, suddenly resigned, leaving his seat vacant from next week and shrinking the Republican’s slim majority in the House to 218 to 213. Previously, he had announced his intention to retire from Congress at the end of his current term.

When asked by Axios whether he was coming under pressure from colleagues over his decision, Buck then hinted that more colleagues might resign, saying: “I think it’s the next three people that leave that they’re going to be worried about.”