Professor of Irish politics Paul Bew said if the movie turns out to be a simple Irish versus British tale of a hardcore group using violence to achieve political goals, it may give ammunition to today's militant republicans in their bloody campaign to shatter the peace process.

Easter Sixteen will feature Guy Pearce and Ian Hart, who had a part in the last big-budget film featuring the rising, Michael Collins, starring Liam Neeson.

Nicola Charles, producer of the upcoming £17 million movie, has described it as a portrayal of "hope and heroism" in a "fight for freedom".

She said in an interview with a Sunday newspaper that she felt the men in the rising were "not essentially rebels" – and that the movie has left itself open to be "ripped apart" by historical purists.

The movie is currently advertised under the tagline "Stop the war. Start the revolution".

Prof Bew from Queen's University told the News Letter yesterday that the movie needed to explain the intricate politics behind the rising to avoid dissidents taking it out of context.

"It was quite clear from the way she (the producer] was talking that it may come across as simply an Irish-British story," he said.

"Of course it is important to respect the principle of artistic freedom, and it may be the case the film-makers will find a way of respecting the complexities of the story.

"But I hope this film doesn't resort to the same old simplistic cliches of 'We the Brits, and our imperialist guilt and what we did to the Irish'.

"The circumstances surrounding Easter 1916 were much more complicated than that."

Prof Bew said a vital target of the rising was not just the British, but also the democratically elected Irish leadership.

He said that the story of the rising is the decision by an unelected politically motivated group to destroy the democratic leadership of Irish nationalism.

The academic said the idea of small diehard groups appointing themselves to defy the will of most nationalists by continuing to wage their "war" had "obvious parallels" with the actions of today's Real IRA and Continuity IRA.

Members of the Real IRA used Easter statements over the Bank Holiday to issue chilling threats that they were going to kill Martin McGuinness and resume terror attacks in England.

Producer Ms Charles has insisted Easter Sixteen – scripted by Belfast-born writer Brendan Foley – does not romanticise the 1916 rising, when rebels tried to seize control of Dublin from the British forces.

She told a Sunday newspaper: "It's a film that has to be made and Foley has spent 14 years working on the script.

"The film is really the prequel to Michael Collins. Our final scene is their opening scene.

It's a human interest story and in no way does it glorify violence."