Mitt Romney will vote to convict President Trump in his Senate impeachment trial, the Utah Republican and frequent critic of Trump announced Wednesday, ending the chance of a unanimous GOP acquittal.

Romney made public his decision two hours before the Senate will vote on two articles charging Trump with abuse of power and obstruction of Congress. The senator will only vote to convict on the first article, saying he will vote to acquit the president of the obstruction charge.

Romney said he believes the president violated the power of his office by asking a foreign government, Ukraine, to investigate a political rival, former Vice President Joe Biden.

Romney said the president is “guilty of an appalling abuse of public trust.”

“There is no question in my mind that were their names not Biden, the president would have never done what he did," Romney said.

All Republicans except Romney are now expected to stick with the president after a nearly three-week Senate trial featuring a case prosecuted by seven House Democrats and a team of seven lawyers who defended the president against the charges.

It takes 67 votes to convict the president on either of the articles. Most of the Senate’s 47 Democrats will vote to convict the president.

Utah is considered a pro-Trump state, but Romney has been among the most vocal GOP critics of the president.

Romney and Sen. Susan Collins of Maine were the only two Republicans to vote last week to extend the Senate trial and call for new witnesses.

Romney called Trump’s efforts to get both China and Ukraine to investigate corruption charges related to Biden “wrong and appalling.”