Film producer Lord Puttnam has called actor Sir Ben Kingsley "barmy" for insisting on being called Sir.
Sir Ben's latest film opens this week
"I think Ben's barmy, it's a silly thing to do. Within the film industry I'm just David Puttnam," he said in an interview with BBC Radio Five Live.
Sir Ben, 62, was knighted in 2001 and likes to be referred to as Sir. His agent was unavailable for comment.
"I wish I could just get hold of him and say 'wake up'," Lord Puttnam said of Sir Ben.
The Oscar-winning actor said after he had been knighted: "There is no Mr Ben Kingsley anymore. Being a Sir brings with it responsibility."
Sir Ben later criticised a German reporter for calling him Mr Kingsley.
"It's Sir Ben. I've not been a Mr for two years," he said.
A poster for his new film Lucky Number Slevin bills him as Sir Ben Kingsley.
Lord Puttnam is also a Labour peer
The British star's film credits include Schindler's List and House of Sand and Fog. He won an Oscar for his role in Gandhi in 1982.
Lord Puttnam has produced films such as Chariots of Fire and Midnight Express.
He received the Bafta Fellowship, the highest honour from the British Academy of Film and Television Arts, on Sunday.
Sir Roger Moore said last week he prefers to be called "Rog" on film sets.
"As for film posters and opening titles, I don't see the point. Would it really add anything to have one's title included?
"Would more people go to see a film just because it's Sir Roger Moore and not just Roger Moore? I don't think so. I think it's the actor people want to see, not the knight."