The Venice Film Festival has begun with the world premiere of The Ides of March, a thriller directed by and starring US actor George Clooney.
The film, which also stars Ryan Gosling and Philip Seymour Hoffman, is one of 22 films in competition for the top awards at the prestigious 10-day event.
It is up against new films directed by Roman Polanski, David Cronenberg, Andrea Arnold and Todd Solondz.
Jude Law, Gwyneth Paltrow, Madonna and Al Pacino are among the stars expected.
In The Ides of March, Clooney plays a presidential candidate whose campaign becomes embroiled in sexual scandal and dirty tricks.
The film got a lukewarm reception from critics in Venice, though it did receive a four-star review from the Daily Telegraph.
"I don't actually think of this as a political film," Clooney told a press conference on Wednesday.
"I figure you could literally put this in Wall Street, you could put it pretty much anywhere and it's all the same sort of issues.
"It's issues of morality... of whether or not you are willing to trade your soul for an outcome," he continued.
Among the other films in competition are a new adaptation of John Le Carre's Tinker, Tailor, Soldier, Spy, starring Gary Oldman and Colin Firth.
Andrea Arnold's entry is a new version of the Emily Bronte classic Wuthering Heights, while Cronenberg's - A Dangerous Method - tells of the relationship between Sigmund Freud and Carl Jung and stars Viggo Mortensen and Keira Knightley.
Polanski is represented with dark comedy Carnage, starring Jodie Foster and Kate Winslet. Elsewhere, Carey Mulligan appears in Steve McQueen's brother-sister drama Shame.
This year's jury is chaired by Black Swan director Darren Aronofsky, with his fellow judges including the musician David Byrne.
"I can't remember looking at a catalogue of films that has been so exciting," Aronofsky said. "To actually have to watch every one of the movies is a great privilege and a thrill."
A number of films showing out of competition will have high-profile world premieres at the festival.
Pacino has directed Wilde Salome, an exploration of Oscar Wilde's work, while Madonna will unveil W.E., her second film as a director.
The film, which has its premiere on Thursday, is a drama loosely based on US divorcee Wallis Simpson and her relationship with King Edward VIII.