Deadline has the story:
Catherine Tate, who played Tennant’s mouthy companion Donna in the BBC sci-fi show, will play opposite the Doctor Who star in Shakespeare’s Much Ado About Nothing. It’s the first time the 2 have appeared on stage together, although they get on famously. On stage they will be playing lovers who are pretty much extensions of their Doctor Who roles: Benedick and Beatrice’s endless witty sparring threatens to keep them apart forever. Much Ado opens at Wyndham’s Theatre in London’s West End on June 1. Tate can currently be seen in the Jack Black comedy Gulliver’s Travels.
Catherine Tate and David Tennant On Graham Norton Part 1
They are amazing together! The entire show is them having fun with each other.