ANCIENT OLYMPIA, Greece - Priestesses in pleated robes swayed under a scorching sun at the birthplace of the ancient Olympics on Wednesday in the final rehearsal to light the flame that will burn at the London Games.

Far from the political drama embroiling debt-stricken Greece, locals and foreign tourists gathered at the ruins of the Doric temple to goddess Hera to watch as Greek actress Ino Menegaki solemnly stooped to light the torch with a concave mirror.

The flame will serve as a backup if overcast skies loom over Thursday's official ceremony, but weather forecasts predict the event will be similarly blessed by abundant sunshine.

For the first time, male priests danced to the sound of a drum amid the temple's ancient ruins instead of limiting the choreography to the adjacent stadium, organisers said.

With her arms raised towards the sky, Menegaki - playing the role of high priestess - then invoked the sun God Apollo in prayer before kneeling to light the torch in just a few seconds as the sun's rays focused on the parabolic mirror.

On the slopes of the adjacent stadium where Greeks competed during the ancient games, priestesses swirled in a dance inspired by the mythological nymphs - nubile, young maidens in the retinue of a god or goddess - while the male priests performed a version of an ancient war dance, minus the weapons.

Greek actress Ino Menegaki, playing the role of High Priestess, lights the Olympic flame during a dress rehearsal for the torch lighting ceremony of the London 2012 Olympic Games at the site of ancient Olympia in Greece May 9, 2012.[Photo/Agencies]

For many Greeks watching, the ceremony was an emotional moment, offering a reminder of the glorious past of a nation now mired in a deep political and economic crisis that threatens to push it to bankruptcy and out of the euro zone.

"As I was watching the ceremony I was thinking that Greece was once a big power and has since gone through a lot of hard times but as a country has always managed to stay afloat," said Vangelis Vanezis, a 35-year-old Greek who lives in London.

"And so it made me think that perhaps this crisis is something that will come and go and we'll get through it."

The rehearsal ended with the high priestess handing the flame and a fresh olive branch to the first torchbearer Spyros Gianniotis, a Liverpool-born Greek swimmer who won the gold medal in the 10 km open water event at the 2011 world championships.

On Thursday, Gianniotis, who has a Greek father and a British mother, will run with the flame to the monument where the heart of modern Olympics founder Pierre de Coubertin is buried before continuing and handing the flame over to Alexander Loukos, a Briton of Greek origin.

The flame then covers 2900 km across over 40 towns in Greece, including remote ones near the Turkish border and tiny islands in the hands of 490 torchbearers.

It will also pass through five archaeological sites during its eight-day journey across Greece before it is flown to the United Kingdom for a tour before the Olympic Games start on July 27.  

An actress, playing the role of a priestess, releases a dove during the dress rehearsal for the torch lighting ceremony of the London 2012 Olympic Games at the site of ancient Olympia in Greece May 9, 2012.[Photo/Agencies]