Around 700,000 Olympics tickets are yet to be sold while capacity at a number of football games has been reduced, organisers said today.
Locog said 250,000 football tickets were currently on sale while 50,000 tickets are available to buy for other sports at the moment.
In addition to this, 200,000 football tickets and 200,000 tickets for other sports are due to go on sale after being returned by Olympics committees from around the world.
Organisers said there had been around one million football tickets left but these have been cut in half by reducing capacity at stadiums.
A spokesman for Locog said: "We are planning to reduce capacity across the venues by up to 500,000 tickets across the tournament.
"This will involve possibly not using a tier, or an area of a ground, in some of the venues.
"This can apply to men's and women's football, if necessary."
London 2012 chairman Lord Coe insisted that ticket sales were "not in bad shape".
Speaking at the first daily press briefing at the Olympic Park in Stratford, east London, Lord Coe said about 150,000 football tickets would also be available through the Ticketshare programme.
He added: "They are in reduced-size venues of course, we have scaled down the size of those venues.
"We've sold more football tickets than we've sold for anything else.
"We're not in bad shape on tickets. It was always going to be that football tickets were the challenge but I think we'll do pretty well."