The most famous chimpanzees in the UK are to be replaced by a younger model.

The chimps have been used in commercials to advertise PG Tips tea since Christmas 1956, making this the longest-running advertising campaign on British television. They will be superseded by a flock of 20-something plasticine birds created by Aardman, the animation company behind the Wallace and Gromit characters and the acclaimed British Gas adverts.

While tea remains the favourite UK beverage, it has slowly been losing share of spend to mineral waters, coffee and soft drinks. Unilever subsidiary PG Tips hopes the new commercial will persuade more young people to return to tea. The new ads will focus on four animated birds that share a house, and will draw material from the diaries of real-life flat-sharing 20-somethings as they lurch from drama to crisis. Tea will be served to smooth over troubled waters. The first commercial will be broadcast tonight (14 January) during the popular soap series Coronation Street.

PG Tips says it is not killing off the chimp characters for good, as it prefers to keep its options open. A cliffhanger final episode has not been filmed, a wise decision given that the adverts have already come in for criticism by animal rights groups.