Mother first paired Monkey with Vegas in 2001, when it won the task to rebrand ONdigital as ITV Digital. Following ITV Digital's collapse in 2002, the duo have not been seen together on screens.
The new campaign featuring Monkey and Vegas will replace DDB London's T-Birds work, which has run since 2002.
Mother won the £10m PG Tips account in a shoot-out against DDB last week. The account had been handled by DDB since the brand was created in 1930.
Mother and PG Tips declined to comment on the story.
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