Ephraim Sneh, a cabinet minister, accused Vanunu in a television documentary to be broadcast this week of "carrying on his campaign to damage Israel", indicating early release was unlikely. "We will not help him in that," he said. "Israel sees no difference between submitting classified information to an Iraqi intelligence officer or to a newspaper."

The 30-minute documentary is the first the Israeli authorities have allowed to be broadcast about Vanunu, who spent his first 11 years in jail in solitary confinement.

After years in which discussion about Vanunu and his revelations was taboo, the film is expected to provoke public debate about whether he should be freed.

Much of the story - including details of Vanunu's kidnapping after he was lured to Rome by a female Mossad agent - was cut by censors.

Einat Fishbain, the programme's presenter, could not interview Vanunu. "I doubt whether Mordechai knows more about nuclear weapons today than an Israeli child surfing the internet," Fishbain said.

"Many people said he was a traitor and should be locked up. But when we ask what has he done, many can't answer. They think the state caught a monster and they say, 'Thank God he's still behind bars'."