Prince George's County Executive Lawrence Hogan, in preparing for a public employe strike three months ago, tried to get the county police to place a top labor leader under surveillance, according to informed sources.

The surveillance of Charlie Parker, the tough-talking president of one of the union locals, never went into effect, however, because Police Chief John E. McHale rejected the idea and the strike was averted.

Hogan denied yesterday that he had ever sought police surveillance of the labor leader. Said Hogan: "We suggested that they [the police] keep an eye on Charlie Parker if a strike happened because of threats he had made against county employes."

Parker was not available for comment yesterday. Union representative Paul Manner said, "My impression from this is that you can take the man out of the FBI, but you can't take the FBI out of the man. Ironically, he [Hogan] was the one who came out first to condemn Nixon. If there is any politican like Nixon, it has to be Larry Hogan."

"The issue was security and violence," Hogan added. "It was a legitimate police concern, it wasn't harassment of union leaders."

Hogan aide Stephanie Bolick said that the surveillance idea has surfaced as one of many security issues discussed in preparation for an expected strike by 1,500 county workers in March.

Relations between Hogan and union leaders were extremely hostile at that time, and the county executive was preoccupied by the possible strike, its political ramifications and by uncontrolled leaks of information from his inner circle.

When Hogan vetoed a tentative contract agreement reached by his own negotiators and the union bargainers, the union began gearing up for a strike. Then, before the job action was to have started, Parker and other union leaders marched into Hogan's office to deliver a formal strike notice. It was this visit, said Hogan, that sparked the request to have the police watch parker.

Hogan said Parker was "making threats" against him, his son and county employes that day. A few days later, as Hogan and his top advisers planned strike strategy, it was decided that Parker, who had made public statements that a strike would be violent, should be watched by the police. As a result of that decision, Lawrence Hogan Jr., the executive's assistant, called Chief McHale and made the surveillance request.

Sources familiar with the request said that Lawrence Jr. also asked that union representative Paul Manner, who had been one of Hogan's most vocal critics be kept under surveillance, but Hogan and his son have both denied that. McHale said he could not remember the conversation with Hogan's son well enough to recall whether Manner was mentioned.

McHale discussed the request with his top staff officers and then called Lawrence Jr. to recommend against surveillance of Parker, sources said.

"I said I didn't think there was much of a threat. I didn't think it warranted 24-hour, round-the-clock surveillance."