The Maine People’s Alliance is calling for Republican U.S. Senate candidate Charlie Summers to resign his job as secretary of state.

The liberal advocacy group says Summers has an inherent conflict of interest because his office oversees elections. The group also says Summers has shown a willingness to use the job for political purposes by working with the Maine GOP to investigate college students for possible voter fraud and advocate for tighter voter registration rules.

“Summers should resign not just because of the conflict of interest inherent in overseeing his own election, but because of his history of voter intimidation and suppression,” Maine People’s Alliance Executive Director Jesse Graham said in a news release.

The group says Summers promised to not be involved in last year’s referendum campaign on same-day voter registration, but then used his office to “amplify outrageous and false accusations of voter fraud in an attempt to swing public opinion and suppress the vote.”

The MPA has set up a petition on its website to collect signatures calling for Summers to step down.

The Summers campaign did not immediately respond. Summers has said he will remove himself from overseeing the election by delegating those duties to staff. He also has said he will not campaign while getting paid to work as secretary of state.