A Citroën commercial in Britain features an old interview with the late John Lennon in which he exhorts people to leave the past behind. (Canadian Press)

Sean Lennon, the son of late Beatle John Lennon, has reacted to a backlash regarding the use of an interview with the singer in a car commercial.

The Citroën ad, which began airing in Britain in February, features John Lennon saying: "Once a thing's been done, it's been done … Looking backwards for inspiration, copying the past — how is that rock 'n' roll? Do something of your own. Start something new."

"Having just seen [the] ad I realize why people are mad," Sean Lennon posted on the micro-blogging site Twitter on Thursday. "But [the] intention was not financial."

The singer's 34-year-old son defended his mother, Yoko Ono, for allowing the footage to be used, saying she was "hoping to keep dad in [the] public consciousness."

The French car company said they wanted the ex-Beatle, who was shot to death in New York in 1980, because of his "universal, timeless and iconic status." The publicity campaign is meant to be "anti-retro."

After the ad started appearing in mid-February, the company was hit by a wave of criticism that blasted Ono and her son for being sellouts and sullying Lennon's image as a rebel.

Sean Lennon went on to say the idea was to maintain his father's appeal to the young and that television was the best way to do that.

"It's just hard to find new ways to keep dad in the new world. Not many things [are] as effective as TV."