(MEXICO CITY) -- Mexico's long-ruling Institutional Revolutionary Party (PRI), facing a tough test in July 2 presidential elections, has a secret weapon to win the female vote - male strippers.

The PRI, which has governed Mexico for 71 years, entertained around 150,000 citizens of a poor neighborhood just outside Mexico City one afternoon last week with ``The Sexy Boys,'' weekly magazine Proceso reported on Sunday.

The strippers performed for almost two hours, impersonating personalities and super heroes and throwing their clothes in the air in time to music.

Against a backdrop of promotional banners for PRI's candidates for president and other political posts, five of them peeled down to white boxer shorts that spelled out ``Vote for PRI'', Proceso said.

``I'm surprised. I've never seen anything like it in a Mexican political campaign,'' said Josefina Franzoni, analyst at the Mexican Institute of Political Studies.

Women make up 51 percent of the 59 million registered voters for Mexico's election, which pits the PRI against the conservative National Action Party (PAN), running neck-and-neck in opinion polls.

The dancers performed in Mexico state, which is currently governed by the PRI and has the highest number of voters, at 7.5 million.

``It's great that we can see nude men, but I would like to see more (political) proposals,'' said Franzoni.

PAN's candidate, Vicente Fox, has seen his popularity slip, giving PRI a slim lead due mainly to the female vote, an independent newspaper poll said on Monday.

Of 1,542 people surveyed May 27-28 in the nationwide poll, commissioned by the Reforma daily, 38 percent said they supported Fox, down from 40 percent in a May 12-14 Reforma poll.

Labastida held steady at 42 percent, with a strong female and rural backing.