Sen. Susan Collins is expected to announce this week whether she will seek re-election in 2020.

Collins, a Republican first elected to the Senate in 1997, has filed preliminary paperwork with the Federal Election Commission and raised more than $8 million toward re-election, but has yet to formally announce her candidacy.

Collins has said she would make her announcement about re-election this fall and told Politico on Tuesday that this week “will be the end of fall, which is what I said.”

Kevin Kelley, a spokesman for Collins, confirmed she is expected to announce her decision whether or not to run for re-election this week.

The race is expected to be tough for Collins, who gained popularity as a moderate Republican but recently faced scrutiny for her support of Justice Brett Kavanaugh’s nomination to the Supreme Court.

It also comes amid heightened political tensions including the Trump impeachment proceedings, which Collins has tried to distance herself from, saying she would have to act as an impartial juror if impeachment is considered by the Senate.