Topeka ? One of the nation’s few late-term abortion providers is asking Kansas’ highest court to block a grand jury investigation of him and his Wichita clinic that was initiated by anti-abortion groups.

Abortion opponents accuse Dr. George Tiller of violating a 1998 state law restricting late-term abortions, an allegation his attorneys repeatedly have said is unfounded. The grand jury is scheduled to convene Tuesday in Sedgwick County.

Lee Thompson, an attorney representing Tiller, said Wednesday that summoning the grand jury amounts to harassment. Anti-abortion groups forced the county to create the grand jury by collecting nearly 7,900 signatures on a petition, more than three times the number required.

Tiller’s attorneys filed a petition Friday with the Kansas Supreme Court, asking it to prevent the grand jury from convening. The court has not scheduled a hearing.

“This is a proceeding brought for harassment and in bad faith by the petition gatherers,” said Thompson, a former federal prosecutor. “You approach the level of vigilantism, and I think we see that happening in this instance.”

Mary Kay Culp, executive director of Kansans for Life, said abortion opponents sought a grand jury because of Tiller’s influence in state politics and because potential violations of the law have been ignored for years. Kansans for Life is the state’s largest anti-abortion group and was heavily involved in the Sedgwick County petition drive.

“Nothing Dr. Tiller or any of his lawyers do surprises me – nothing,” Culp said. “It makes you have to wonder just what it is they’re so afraid of.”

The legal dispute is unusual. Few states allow citizens to petition to empanel a grand jury, and Kansans haven’t used the power much historically. Also, defendants typically don’t challenge their prosecutions until after they have been convicted.

The grand jury Tiller wants to block would be the second one abortion foes have forced the county to create in 18 months to investigate the doctor. Last year, a grand jury reviewed the death of a Texas woman who had had an abortion at Tiller’s clinic but issued no indictments.