To absolutely no one's surprise, Attorney General Tom Corbett will make the long-awaited official announcement of his candidacy for governor Monday in Pittsburgh.

Brian Nutt, the manager of the soon-to-be-official campaign, confirmed that the state's chief prosecutor will make "a major announcement on his potential candidacy" next week.

"It's a major announcement and no one will be arrested," said John Brabender, Mr. Corbett's media strategist.

The timing of the event was first reported yesterday afternoon on politicspa.com.

Mr. Corbett will join U.S. Rep. Jim Gerlach in the battle for the GOP nomination to succeed Gov. Ed Rendell, who is barred by the state Constitution from running for a third term.

Mr. Gerlach has acknowledged that Mr. Corbett starts as the front-runner in the race. Early polling has shown the prosecutor with a significant edge over his rival, although the same surveys suggest that neither Republican has broad statewide name recognition.

Last year, Mr. Corbett bucked a strong national Democratic tide in easily winning re-election to his Harrisburg post. While it is his second elected term, Mr. Corbett also served as the state's attorney general from 1995 to 1997 when he was appointed to the office by former Gov. Tom Ridge after the resignation of former Attorney General Ernie Preate.

The most high-profile investigation during Mr. Corbett's tenure is Bonusgate, the ongoing probe into the alleged misuse of the Legislature's staff and resources for political purposes.

Mr. Gerlach stopped by the Capitol pressroom in Harrisburg yesterday to repeat his charge that Mr. Corbett has a "conflict of interest" in running for governor while he is still leading the investigation of alleged legislative wrongdoing.

Mr. Corbett's probe of political corruption in the Legislature "while at the same time seeking the support of GOP legislators, party leaders and key contributors is a clear and obvious conflict of interest," Mr. Gerlach said. "He has to resolve that conflict, either by resigning as attorney general in order to campaign for governor, or by suspending his political campaign while he finishes the Bonusgate investigation."

Mr. Corbett has shrugged off the Gerlach attacks on the Bonusgate issue, contending that his soon-to-be-official rival is raising the issue in an attempt to draw attention to his campaign.

So far, Mr. Corbett has charged 12 people -- all Democrats, including two former legislators, in the case. The probe concerns whether some staffers were paid their taxpayer-funded salaries in order to conduct political campaign work in 2006, which would be illegal. Mr. Corbett has indicated more arrests are coming at some point, and some of those could be Republicans.