US director Wes Anderson brings his whimsical touch to the opening with Moonrise Kingdom, a pre-teen elopement fantasy whose star-packed cast includes Bruce Willis as a small-town cop and Bill Murray as a morose parent.

But before the celebs grace the red carpet for the gala premiere, Sacha Baron Cohen's zany alter ego General Aladeen, star of The Dictator, will try to hijack media attention with a stunt in front of the Carlton hotel.

The Ali G, Borat and Bruno star, who turned up in military regalia at the Oscars and pretended to pour late North Korean leader Kim Jong-Il's ashes onto an interviewer, has already premiered his movie and is in Cannes simply to cause a stir.

Baron Cohen strutted his stuff on the beach here in a “mankini" in 2006 to promote Borat. Workers were rolling out the red carpet on the steps of the waterfront festival palace on Wednesday morning as Cannes braced for the annual onslaught that sees its population triple to 200,000.

Diehard movie fans set up their stepladders across the road from the magical steps to make sure they get a fix on the stars as they drive up in their limousines. Nicole Kidman, Brad Pitt and Robert Pattinson are among the Hollywood royalty who will join high-brow film-makers at the Riviera resort for the next 12 days at the world's top movie showcase.

This year, Egyptian director Youssry Nasrallah represents Egypt with his Baad El-Mawkea (After the Battle), starring Menna Shalaby and Bassem Samra. Nasrallah is the first Egyptian to compete at Cannes after Youssef Chahine. Though this is Nasrallah's first participation in the official competition, his debut Sarikat Sayfeya (Summer Thefts) was screened in the parallel director section in 1988. His Bab El-Shams (Gate of the Sun), based on a novel by renowned Lebanese author Elias Khoury, was selected outside the competition in 2004 and last year there was a special screening of 18 Days, of which he directed a segment.

This year's bash also features druggy road trips, soul-searching drama and stylish gangland flicks and sees the return of such Cannes grandees as David Cronenberg, Ken Loach and Michael Haneke. Star-wise, the 2012 line-up promises to dazzle with Kidman, Marion Cotillard, Jessica Chastain, Kylie Minogue, Kristen Stewart, Pattinson and Pitt – just a few of the A-listers expected in town.

The festival will also feature its usual dose of champagne-fuelled parties, high-stakes movie deal-making, and publicity stunts such as Baron Cohen's beachfront intervention. Twenty-two films -- none of which was directed by a woman -- are vying for the coveted Palme d'Or award at the festival's glitzy gala finale on 27 May. Palme d'Or-winner Nanni Moretti of Italy heads up a nine-strong jury -- which includes actor Ewan McGregor and fashion designer Jean Paul Gaultier -- that will pick the winner.

Moretti was due to hold a press conference later Wednesday ahead of the evening opening ceremony. Two US mavericks are running for Cannes gold: Lee Daniels's keenly awaited The Paperboy stars Kidman opposite John Cusack and Zac Efron in the tale of a reporter investigating a death row case. The second is Jeff Nichols, whose Mud, about two teenage boys who form a pact with a fugitive, was a surprise entry. Canada's Cronenberg brings Manhattan thriller Cosmopolis, adapted from Don DeLillo's novel and starring Pattinson as a billionaire asset manager journeying through the city in a stretch limo.

Brazil's Walter Salles has adapted Jack Kerouac's cult novel On the Road, while Australians John Hillcoat and Andrew Dominik bring two US-set works: bootlegging drama Lawless and the mobster flick Killing Them Softly. Among the European giants, Austria's Haneke will show Amour (Love), starring Isabelle Huppert as the daughter of a woman hit by a stroke.

Britain's Loach returns for the 17th time with the comedy The Angel's Share, about ex-offenders who turn to whisky-making. One of three French filmmakers in the race, Jacques Audiard has cast Cotillard as a killer-whale trainer hit by a tragedy in Rust and Bone.

Romania's Cristian Mungiu, who scooped the 2007 Palme for a Communist-era abortion drama, returns with Beyond the Hills about two orphans, while Italian Matteo Garrone takes on TV culture with Reality. Politics holds a slot in the Palme d'Or race with "After the Battle" by Egypt's Yousry Nasrallah, about the Arab Spring, while French philosopher Bernard-Henri Levy shows an out-of-competition documentary on the Libyan war. Asia gets a look-in with two South Koreans: Im Sang-soo with erotic thriller Taste of Money, and Hong Sang-soo with In Another Country. And Palme-winning Iranian Abbas Kiarostami returns at 71 with Like Someone in Love, a Japan-set tale about a student who works as a prostitute. Last year's jury chaired by Robert De Niro crowned Terrence Malick's The Tree of Life starring Pitt and Sean Penn.