With thousands of Republicans set to invade the city this summer, high-priced escorts and strippers are preparing for one grand old party.Agencies are flying in extra call girls from around the globe to meet the expected demand during the Aug. 30-Sept. 2 gathering at Madison Square Garden.

“We have girls from London, Seattle, California, all coming in for that week,” said a madam at a Manhattan escort service. “It’s the week everyone wants to work.”

“It’s going to be big,” agreed one operator at a midtown escort service.

Charging from $300 to upwards of $1,000 for an hour of companionship and a whole lot more, escorts said they can always count on conventioneers for big business.

“It doesn’t matter what party you come from,” said Robyn Few, a $500-an-hour California call girl who now runs Sex Workers Outreach Project, an advocacy group. “When you want to buy sex, you will.”

That’s the hope among escort services expecting a windfall from randy Republicans.

“We’ve got everything organized – the hotels, the flights, the advertisements,” said another escort service operator. “We’ll probably have 60 girls that week, instead of the usual 30.”

Political conventions have long been a boon for the sex industry.

At the 1992 Democratic convention in New York, bikini-clad female oil wrestlers dropped their tops on a flatbed truck in front of Madison Square Garden.

At the 1996 Republican convention in San Diego, an escort service in search of delegate dollars changed its name to GOP: Good Old-Fashioned Pleasure.

While many escort agencies operating on the sly out of Manhattan hotels and apartment buildings welcome the influx of potential customers, others are wary of increased police attention.

“We’re just being very secure,” said a woman who runs an agency in midtown. “So we won’t be taking on any out-of-towners.”

NYPD spokesman Sgt. Kevin Hayes said, “Our quality-of-life and crime reduction efforts will remain intact.”

Tracy Quan, author of the autobiographical novel, “Diary of a Manhattan Call Girl,” said she worries cops will crack down on the most visible sex workers.

“I get depressed whenever there’s a big political convention because I know the street girls are going to be hassled, arrested and treated like criminals,” Quan said. “All in the name of ‘cleaning up’ our city for these people from out of town.”

The players on the legal end of the city’s sex industry have no such worries – and strip club owners are salivating at the prospect of crowds equipped with bunches of big bills.

Clubs have started booking private parties for delegates anxious to ogle topless beauties after a day of watching fully clothed politicians boast about family values.

“We have our show down to a science,” said Lonnie Hanover, a spokesman for Scores, the upscale topless club. “We’ll be full every night with what we think are the best-looking girls in the industry.”

Hanover said Scores – which recently opened a branch just blocks from the Garden – has lined up several big-name entertainers for the convention. “But we don’t reveal them,” he said.