The International Olympic Committee's monitoring team began a three-day visit to London on Tuesday to check on progress for the 2012 Games.

The Co-ordination Commission is touring Olympic sites and will be given briefings on progress in the last year.

One area of potential concern is the Olympic Village, where work is due to start next month without a contract with the constructors.

But the Olympic Delivery Authority (ODA) insists plans are on track.

It admits that the "challenging" global economic climate has made agreeing a final deal with Australian firm Lend Lease more difficult.

But it says interim agreements will allow the work to start in June.

An ODA spokesman said: "The Olympic Village site is now clear. Planning applications for the first blocks of the flats have now been submitted and Lend Lease are due to start piling next month.

"We expect to sign interim agreements shortly and aim to have financial arrangements in place before the main build later this year.

"The changing economic situation remains a challenge but we remain on-programme."

The IOC visited venues including Wembley Stadium on Tuesday morning and went on to meet the main London 2012 project leaders.

These include London 2012 chairman Sebastian Coe, Olympics minister Tessa Jowell, British Olympic Association chairman Colin Moynihan and ODA chairman John Armitt.

New London mayor Boris Johnson will also address the IOC team on Tuesday.

The Co-ordination Commission will devote Wednesday to updates on issues involving sport, marketing and athletes, and on Thursday will deal with cultural, communications and financial issues.

BBC Radio 5 Live's Gordon Farquhar said there should be plenty for them to see.

"Whilst the domestic agenda may have been dominated by rows over funding, the IOC team will be mores interested in find out how closely their master schedule is being followed and what has been achieved in the last 12 months," he said.

"LOCOG (London Organising Committee of the Olympic Games) is way ahead of previous organisers in terms of raising finances, if not erecting buildings.

"There have been frustrations, but the Olympic site has been cleared, the power lines are buried and work on the venues is close to starting - ahead of schedule in the case of the main stadium."