Two groups are better impersonated on television than by theatre: the Royal Family, and East Enders.   In H R Haitch they collide awkwardly in a royal wedding spoof musical with all the elegance of a bin lorry ram-raiding Buckingham Palace.

Despite a workable pub set that could have been borrowed from the adjacent Lord Nelson, this rough-and-ready story where chinless prince meets chavvy barmaid before she knows his true identity is equally underwritten and overacted.

Tori Allen-Martin does her best as barmaid ‘Chelsea’ with thin material and an abrasively bobbled pink knit sweater dress, but sounds more credible and endearing when singing the wistful numbers in her own voice than hamming the East Laaandaan accent. Why can’t any fringe company deliver royals or cockneys without caricature?

Sticking to fashion, in the sort of leopard print and burgundy vinyl skirt Angie Watts wouldn’t have worn to put the empties out, Andrea Miller gives excellent value both as a slutty pensioner, and what you hope has a grain of authenticity behind closed palace doors – as a wonderfully foul-mouthed and vituperative Queen.

Christian James sings sweetly and has the gauche mannerisms of a gormless princeling down pat.  He also deserves better work.  Despite development since its workshop production, H R Haitch is still incomplete, unsteadily staggering between satire, parody and farce until the second act dissolves into a predictable pantomime happy ending.

There are some good laugh lines, though, but also strange running gags about referenda, the Olympics and Uber that make the show feel needlessly dated.

Especially while the real soap opera is happening down the road in Windsor.

Until 2 June