James Franco, driving, is pictured here with Canadian Seth Rogen in the stoner action-comedy Pineapple Express. James Franco, driving, is pictured here with Canadian Seth Rogen in the stoner action-comedy Pineapple Express. (Sony Pictures)

Actor James Franco says he can't give a commencement speech at the University of California in Los Angeles (UCLA) because he'll be working on his next film, a move that comes after heated opposition from students.

The actor, last seen in Milk and Pineapple Express, said in a statement Friday that he had to cancel his June 12 appearance because it conflicted with his work demands on the film Your Highness, set to start shooting next month in Ireland.

UCLA announced Saturday on its website that Linkin Park lead guitarist Brad Delson, who graduated from the university with a bachelor's degree in communication studies in 1999, would replace Franco.

The actor's sudden dropout seems suspicious in light of the controversy his upcoming commencement address had stirred up.

Soon after university officials announced Franco's appearance in March, UCLA senior Erin Moore set up a Facebook page called "UCLA Students Against James Franco as Commencement Speaker."

Soon, Moore had hundreds join in, estimating that 80 per cent of them were UCLA students.

"The problem with him as a speaker comes down to the fact he was a peer for so many of us," Moore said.

"He was in our class. He's not a role model. And he hasn't had time to accomplish anything with his degree."

The 31-year-old performer enrolled at UCLA in 1996 and graduated in 2008 with a degree in creative writing.

Those two facts would have made him both the youngest person and most recent graduate to deliver a commencement address at the university.

With files from The Associated Press