A �40 million programme of key test events will be vital to “challenge” and try out new venues, equipment and staff in time for the Games, London 2012 chief executive Paul Deighton said.

The year-long schedule starting this month covers 42 events - many set to feature 2012 medal hopefuls - at 26 venues, among them the BMX track within Stratford’s Olympic Park in late August.

The programme is designed to create the kind of issues that could happen during the Games.

Up to 250,000 spectators across all the events will be able to watch what London 2012 is billing as the “world’s largest rehearsal” during the testing series, called London Prepares.

More than 10,000 volunteers, 8,000 athletes from more than 50 countries and more than 250,000 spectators will be part of a 12 month rehearsal.

The programme will focus on testing the sporting field of play; results, timing and scoring systems; how teams work together and how people move around venues.

The four events this summer that will be ticketed are:

Mountain Bike: July 31 – Hadleigh Farm, Essex; Beach Volleyball: August 9-14 – Horse Guards Parade; Basketball: August 16-21 August – Basketball Arena, Olympic Park and BMX: August 19-20 August – BMX Track, Olympic Park.

Other events newxt year that are ticketed are: Gymnastics - North Greenwich Arena and in the Olympic Park; Cycling – Velodrome; Diving; Synchronised Swimming; Water Polo - Aquatics centre; Hockey: Hockey Centre; Wheelchair Tennis; Paralympic Athletics and Athletics:

There are also free events to watch, such as the Cycling – Road Race event on August 14 in Surrey.

Paul Deighton, LOCOG Chief Executive, said: “The London Prepares series is essentially about putting our plans into practice. Although our venues won’t be dressed in their Games finery, a number of events will give the public a chance to see some world class sporting action ahead of next year.”

For details visit: www.london2012.com.