Monty Python's Spamalot, a musical rehashing of the 1975 film Monty Python and the Holy Grail, has won a top honour in American theatre, picking up this year's Tony award for best new musical.

Spamalot, which has received mixed but generally positive reviews in the US, has been the biggest show on Broadway since it opened on March 17.

Ben Brantley, the influential theatre critic of The New York Times called the musical "amusing, agreeable, forgettable", and identified it, along with Mamma Mia, as part of a growing trend of Broadway productions that repackage a well-known product with a sure fanbase.

Although a British audience might find much of Spamalot dated and wincingly familiar, the show has been sold out at the Schubert Theater in New York, and its strange combination of knights who say "ni" and parody of musical theatre was enough to bring in three awards at last night's ceremony.

Director Mike Nichols, whose recent work includes his production of the more cerebral Angels in America for HBO television, won for best direction of a musical and Sara Ramirez won a Tony for her portrayal of The Lady in the Lake. The cast also includes Tim Currie and Hank Azaria, the film star who supplies the voices of Moe and Apu in the Simpsons. "Spamalot" was written by former Python, Eric Idle.

Although Spamalot had the most award nominations, 14, the biggest winner at last night's ceremony was rival musical, The Light in the Piazza, a romance about a mentally ill woman who finds love in Italy that picked up six awards. Doubt, a drama about a Catholic school in the Bronx, was named best new play.

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