According to a BBC article, the family of Field Marshal Douglas Haig objected to what they felt was a crudely mocking portrayal of him in the show and tried to prevent the show from moving to a West End run after its run at Stratford East. Cast member Victor Spinetti remembered a performance that Princess Margaret attended in the company of Lord Cobbold, who was the Lord Chamberlain. In that capacity, he was the official censor of theatrical productions, and he could have prevented the move.
According to Spinetti, "Afterwards Princess Margaret came backstage and said 'Well Miss Littlewood those things should have been said many years ago - don't you agree, Lord Cobbold?' He gave a thin smile and said 'Oh yes ma'am'. And Joan knew that was our permission to go into the West End."