PITTSBURGH — Two former staffers testified Monday at a preliminary hearing for state Supreme Court Justice Joan Orie Melvin that they felt uncomfortable when they were asked to do political work for Melvin.

Melvin, 56, is accused of illegally using her taxpayer-funded staff when she was still a Superior Court judge to campaign for a seat on the high court in 2003 and again in 2009, when she won her Supreme Court race.

A grand jury found sufficient grounds to charge Melvin. A judge was hearing evidence Monday to determine if prosecutors have enough evidence to take the case to trial.

The first witness for prosecutors was Molly Creenan, a former Melvin staffer who said she was asked to work a poll on election day.

Creenan said she knew it was against the law and that she expressed concerns to her supervisors and directly to Melvin. She said she also observed a state-owned printer, copier and fax machine being used for political work.

Melvin, a conservative Republican from Pittsburgh’s North Hills suburbs, has denied the charges and suggested they’re a political vendetta by the county’s Democratic district attorney, Stephen Zappala Jr.

Former Melvin staff member Lisa Sasinoski also testified, saying she was present when state staffers were told they had to work a poll. Sasinoski said she also was pressured to “make up” expense vouchers for Melvin’s campaign, and that she was fired in December 2003 after complaining about what she called “nonstop” illegal campaign activities.

The hearing was expected to last at least two days.