THE CHAIRMAN of the Montgomery County Republican Committee is under investigation by county authorities for alleged sexual assault, sources with knowledge of the probe told the Daily News yesterday.

The GOP chairman, Robert J. Kerns, a partner in a Lansdale law firm, allegedly got drunk Oct. 25, the night after a major GOP power-broker dinner, and sexually assaulted a woman with whom he worked, according to the sources, who spoke on the condition of anonymity.

No charges had been filed by the Montgomery County District Attorney's Office as of last night. Kerns, who is married and has two grown sons, did not return calls from the Daily News seeking comment.

"Somebody alleged that he was drinking and sexually assaulted her," said one source. "It was supposedly a woman that worked with him. It took place the following evening, 24 hours later - not associated with the county dinner."

When asked by phone Tuesday about the allegation against Kerns, both Pennsylvania Republican Chairman Robert Gleason and prominent Montgomery County GOP leader Thomas J. Ellis said they "can't talk about that."

Investigators have been seen at Kerns' home and at his law office, both in Upper Gwynedd, NBC10 reported last night. At least one search warrant was filed seeking potential evidence in the case, the station reported.

The alleged assault took place one night after Gov. Corbett headlined the Oct. 24 GOP annual fall dinner at Westover Country Club in West Norriton, Montgomery County. That event was hailed by Kerns as a long-awaited peace agreement after party bigwigs in the county had been split for more than two decades.

The discord among Montgomery County Republicans has been blamed for lackluster turnouts and results at the polls in recent years.