A lottery game to help fund the London 2012 Olympics and Paralympics has been launched seven years to the day before the Games' opening ceremony.
Sebastian Coe displays the new Olympic scratch card
The new scratch card is one of a series of games expected to raise £750m by 2012 - part of £1.5bn of lottery money going towards the Olympics.
Olympics Minister Tessa Jowell said the game was being launched now to give it enough time to raise that money.
The 'Go for Gold' cards will cost £1 each and will go on sale on Thursday.
Dianne Thompson, chief executive of the Lottery operator Camelot, said that 28p in every pound will go to the Olympic Lottery Distribution Fund.
More than 11m cards will go on sale from Thursday and players will have a one in 4.93 chance of winning. There will be 11 levels of cash prize, with nine people winning the top prize of £2,012.
The Games are expected to cost a total of £2.375bn and London 2012 committee chairman Sebastian Coe believes the card will be vitally important for the fund-raising effort.
"Seven years from today we will be just a few hours away from welcoming the world to the opening ceremony of the London 2012 Olympic Games," he said.
"The new Go for Gold scratch cards will provide key funding to make the Games happen.
"Camelot have a very good record for raising money, certainly for good causes.
"The British lottery is one of the few lotteries in the world that is actually on a rising income, so I am very confident that that will be achieved.
"These will be magical Games and a Games for everyone, it is a UK-wide project. We are set for a very exciting seven years."
Ms Jowell added on BBC Radio 4's Today programme: "The Lottery needs to raise altogether £1.5bn of which we estimate that £750m over the seven years between now and the Games will come from the new Olympic lottery game.
"£340m will be allocated from existing elite sport programmes which are funded by the other sport lottery distributor.
"Anything up to £410m will be reallocated from other good causes in the immediate run-up to the Games, depending on the funding needs at the time.
"It is important that we launch the game now in order that we build up the income stream that will be able to fund the development of the new infrastructure, the sporting infrastructure, the venues that will host the Games in seven years' time."
Security at London 2012 would be a "major challenge", Jowell added.
"Over £200m has been budgeted within the Olympic funding package to meet the security concerns; security will be built in, it will be designed in, to every one of the Olympic venues and to the Olympic village," she said.
"London and the UK are open for business and the best way that our allies can show their solidarity with the people of London, and particularly those families who lost their loved relatives on 7 July, is to come here and support us."
Ms Jowell and Coe were joined by an array of gold medal winners to launch the lottery game.
Among those present were Danny Crates, who took gold in the 800m at the 2004 Paralympic Games in Athens; Denise Lewis, the heptathlon champion at Sydney 2000; Shirley Robertson, double Olympic gold medallist in sailing; and Daley Thompson, who won the Decathlon in 1980 and 1984.
The new game is set to be the first in a series of dedicated Olympic lotteries.
Future games could be internet based, as well as themed around one-off events such as the Beijing Olympics in 2008.
An Olympic-themed television game show is also being looked at but the plans will depend upon approval by the National Lottery Commission and the International Olympic Committee.
BBC sports news correspondent Andy Swiss said Olympic organisers were keen to introduce the new game while the success of London's bid was fresh in people's minds.
Other streams of revenue will come from International Olympic Committee TV and marketing deals; sponsorship and official suppliers; ticket revenues and licensing.
The planned council tax increase (38p a week for Band D houses), which will raise a further £625m, will not be introduced until next April.
A further £250m will come from the London Development Agency, an organisation set up by Mayor Ken Livingstone to promote economic growth.
The government is spending £800m redeveloping the Lower Lea Valley and £7bn on London's transport infrastructure, but none of this is being funded from the Olympic budget.
Meanwhile shadow sports minister Hugh Robertson has called on the Government to use a predicted £320m tax windfall from the lottery to help cut the cost to Londoners of hosting the Olympics.
Robertson said: "If the Government wants to give its full support to the Olympics and to British sport, it should use this money either as a reserve fund to protect London's council tax payers from footing the bill for any overspend from 2012 or to create a legacy fund to encourage young athletes."
How can the capital get ready in time for the Olympics? Are lottery scratch cards a good way of raising money? Who do you think should work with Lord Coe on the Olympics 2012?