THE creator of Ali G and Borat has been persuaded by Steven Spielberg to move from comedy to serious politics by playing a hippie opponent of the Vietnam war.

In The Trial of the Chicago Seven, Sacha Baron Cohen will portray Abbie Hoffman, a figure from the 1960s counterculture who used a series of pranks to campaign against the war. Baron Cohen is expected to be paid about £3m for the film.

Baron Cohen, 36, became famous in Britain for his Ali G persona in the 1990s but won international acclaim with last year’s film Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan. He has now “retired” his Borat character.

The Spielberg film is said to be closer to Munich, the director’s exploration of the morality of political assassination, based on the 1972 terrorist attack on the Olympic Games, than to his next Indiana Jones frolic, due in the summer.

The Trial of the Chicago Seven follows protesters who disrupted the 1968 Democrat party convention with an anti-Vietnam-war “carnival” that turned nasty. Demonstrators threw bricks, police responded with tear gas and the centre of Chicago was engulfed in flames. Curfews only escalated the violence.

After the clashes, independent investigators blamed eight police officers and eight protesters including Hoffman, who had already disrupted the New York Stock Exchange with showers of fake money.

The police were not charged but the protesters were accused of inciting a riot. One was jailed for contempt, leaving the seven to fight the charges.

It was, said the late writer Norman Mailer, who testified for the seven, a noisy televised clash between the old order and the burgeoning counterculture.

Hoffman went on to become an irascible celebrity who, later diagnosed with a bipolar disorder, killed himself with pills in 1989.

Baron Cohen will not have to undergo a big transformation to play the part. Hoffman, who was Jewish, attended Berkeley University in California, while Baron Cohen, an urbane Orthodox Jew more than 6ft tall, cut his teeth entertaining friends at Christ’s College Cambridge with subversive wit and surreal pranks.

Baron Cohen is already planning a return to the screen in the guise of Bruno, a camp Austrian fashion show presenter with an unpleasant line in Nazi jokes. It is reported he will receive a £7m advance and 15% of box-office receipts for the role, a record for a British comedian.

He is still fighting writs for slander and fraud from several people lampooned in the Borat movie, including the villagers of Glod in Romania where the opening sections of the film were shot.

Explore Film

• Film Reviews

• Trailers

• DVD

• Oscars

• Cannes

Editor's choice

• U2 at Nou Camp Stadium, Barcelona
• The 50 Best Movie Villains
• The 15 golden rules of theatre etiquette