'The Avengers' is an allegory, says Mark Ruffalo

Avengers star Mark Ruffalo has revealed details of the superhero crossover project.

The actor, who plays the Hulk in the Joss Whedon-helmed film, told The Wall Street Journal that its story is an allegory for Americans.

"You have all these disparate egos, superheroes in this and that, and they refuse to give up some of their positions in order to make a more perfect union and to join the team," said Ruffalo.

"That's really what the whole movie is about - subjugating your own best interest momentarily to further that of the whole."

Ruffalo's Hulk will line up alongside Captain America (Chris Evans), Thor (Chris Hemsworth), Iron Man (Robert Downey Jr), Hawkeye (Jeremy Renner), and Black Widow (Scarlett Johansson) when the movie arrives in theatres in May.

Avengers also stars Samuel L Jackson as SHIELD agent Nick Fury, and Tom Hiddleston as Loki. It was recently reported that Captain America foe Red Skull could feature as an additional villain.

The Avengers arrives in cinemas on April 27 in the UK and on May 4 in the US.

> The Avengers debuts new character pictures

Watch the Avengers trailer below: