The move comes amid growing theatre industry belief that the top prices for top West End shows, which range between £40 and £65, are too expensive for ordinary London theatregoers.
Sir Cameron said: "Avenue Q is alive and more than kicking but research has shown that there is a market for an audience who would come to off-peak performances and pay a top price of £35. I want an increase audiences at a price that theatregoers want to pay.