Three Clayton County commissioners and two top officials are asking a judge to prohibit the district attorney and her staff lawyers from directing a special grand jury that is investigating them.

Commissioners Sonna Singleton, Gail Hambrick and Wole Ralph; County Manager Wade Starr; and finance director Angela Jackson said in the court filing District Attorney Tracy Graham Lawson was using the work of that investigative grand jury to raise campaign funds and to ask for support for her re-election campaign. They attached a copy of a campaign letter Lawson sent supporters in May.

"The contents of this solicitation make it clear that Ms. Graham Lawson is using the fact that she is investigating the [five officials] for the purpose of raising funds for a political purpose," said the "motion to disqualify" that was filed Wednesday.

The court filing quotes American Bar Association standards that say a prosecutor should not let personal circumstances affect professional decisions. The ABA standards "provide that where there is any implication or appearance of partiality or conflict of interest might cast a shadow over the integrity over the office of the district attorney, district attorneys must recuse themselves."

Public corruption investigations by this special purpose grand jury, impaneled in April 2011, have already led to a resignation, a guilty plea and indictments against former Sheriff Victor Hill and former Morrow city manager and onetime City Council member John Lampl.

In recent months, grand jury search warrants have been executed on the offices of all five Clayton County commissioners, the finance director and the county manager.

Graham Lawson declined to comment. She said she had been "on leave" Wednesday and had not seen the filing, which asks for a court hearing. "I will be happy to look at it tomorrow ... and answer questions, if I can, at that time," she said.