The London Olympics will create “a thriving district of new communities”, the mayor and ministers pledged on Tuesday as they published a detailed masterplan for the legacy to be left by the 2012 Games.

In spite of the rising costs of building the games venues and a lack of public sector financing, Boris Johnson, London mayor, expressed confidence that the £1bn legacy plan would boost prosperity in east London and signal the area’s “new importance in a 21st century London”.