Cast members — including the leads Roger Allam and Conleth Hill — will make the jump with it. The play, about West German politics in 1969 — and specifically the relationship between German Chancellor Willy Brandt and his P.A. and Stasi spy Gunter Guillaume — has been a big hit for Frayn and the National Theatre. It has won both the Critics’ Circle and the London Evening Standard awards for Best Play. Frayn himself, accepting the Critics’ Circle bottle of champagne, said how surprised he was that such a boring-sounding subject should do so well. Next time, he quipped, he’d deliver a play about power-play in a regional English council.

After its stint at the Lyttleton, the show will transfer to the West End’s Wyndham’s Theatre in April. It’s also set to reach Broadway in a £2.5-£3 million leap across the Atlantic. There’s no reason why the associated American producers Bob Boyett and Bill Haber should wait for the London run to finish — the show’s director, Michael Blakemore, has said that he would like to cast a New York production with American actors.

With the National’s production of Tom Stoppard’s Jumpers (starring Simon Russell Beale and Essie Davis) also scheduled to make the move to New York, and Howard Davies’ award-laden staging of Mourning Becomes Electra (with Helen Mirren and Eve Best) possibly to follow, it looks as though Tony voters may have an embarrassment of NT riches to consider for this year’s ceremony.