Haydn Gwynne, Robert Hardy and Paul Ritter will join Helen Mirren in “The Audience,” the new West End play about the queen by Peter Morgan (“Frost/Nixon.”)

Gwynne (“Billy Elliot”) will play Margaret Thatcher, while Hardy is on board as Winston Churchill and Ritter (“The Norman Conquests”) is set to portray John Major. Mirren will once again play Queen Elizabeth II, a character she also portrayed in the Morgan-scripted 2006 film “The Queen.”

Beginning preview at the West End’s Gielgud Theater Feb. 15 ahead of a March 5 opening, Morgan’s play imagines a series of meetings between a succession of U.K. prime ministers — from Churchill to current incumbent David Cameron — and their queen as she moves from young mother to grandmother.

Helmed by Stephen Daldry, “The Audience” is produced by Matthew Byam Shaw for Playful Prods., Robert Fox and Andy Harries (“The Queen”).

Bob Crowley (“Once,” “The History Boys”) designs sets and costumes while Rick Fisher (“An Inspector Calls,” “Billy Elliot”) provides lighting. Further casting will be announced shortly.

In further West End casting, Brit actor Gavin Lee, who originated the role of Bert in “Mary Poppins,” will leave the Gotham production of that show to take over the lead in the hit West End production of “Top Hat,” the role played in the original RKO motion picture by Fred Astaire. Lee takes over from Tom Chambers in February, and will play opposite Charlotte Gooch, who joins the Kenny Wax production on Nov. 27.