London's preparations for the 2012 Olympics are well on track even if no venues have yet been started, deputy chairman of the organising committee Keith Mills said on Sunday.

"We have made huge progress in the Olympic Park which is obviously the biggest part of the construction project," Mills told BBC Radio.

"We have built four kilometres of tunnels for all the cabling which we need for the venues. There's a lot of construction going on but it's mainly underground."

Britain has a patchy record in delivering major sporting venues, but Mills said this year will see considerable progress towards delivering the 2012 Games.

"This year all the buttons will start being pressed, so it's an exciting time," he said. "We have the most enormous project plan and we are absolutely on target.

"The planning permission we've been waiting for should come through at the end of this month and we now own 96 or 97 percent of all the land that we need.

"The contracts for the five big venues should go out to tender this year."

The 2012 project came under fire over budgets last year, with Olympic Minister Tessa Jowell admitting that the projected costs of building the Olympic Park in East London had risen by 900,000 pounds ($1.78 million) to 3.3 billion.

The total cost of regenerating what is a neglected area of London is likely to be much higher, with some estimates in excess of 10 billion pounds.

Mills recently announced that he is putting together a British team to challenge for the America's Cup yacht race with a budget of 30 million euros (US$38.88 million) a year.