The team behind London's bid for the 2012 Olympics will on Thursday debate which consortium will draw up the plans for the games.
Their blueprint will have to show where major venues like the Olympic stadium and village will go.
But whoever wins the competition will only have until the end of November to come up with their ideas.
The location most likely for the games will cover thousands of acres of the lower Lea Valley, a rundown area of east London.
The winning group will also have to outline how this area will be regenerated, even if London is unsuccessful with its bid.
Six groups are vying for the contract including consortiums headed by Lord Foster, the man behind City Hall, and Lord Rogers, the Mayor of London's advisor on architecture.
The Swiss architects who created the Tate Modern, Jacques Herzog and Pierre de Meuron, also make the shortlist, as do EDAW/HOK the team behind the new Wembley Stadium.
The other two are Terry Farrell and Partners and MBM Arquitectes.
An announcement is due to be made on Friday.