The Mayor has spent £8,000 on the 5,000-capacity venue for People's Question Time, but the highest turnout for his Q&A evenings was 870. The last event, in Greenwich, attracted between 860 and 870 people, said a London Assembly spokeswoman. But one in Croydon two months ago was attended by just 350. A spokesman for the TaxPayers' Alliance, said: "This venue is clearly too large and too expensive."