USA's Justin Gatlin arrives at the Games Terminal with an Olympic Torch at Heathrow Airport, London. PIC: PA Wire/Steve Parsons

Heathrow airport is braced for one of its busiest days ever.

Thousands of Olympic athletes and officials are mounting an exodus from London.

Around 116,000 people will depart from Heathrow today (Monday), making it one of the west London airport’s busiest-ever days.

This compares with around 95,000 who would be departing on a normal day

The all-time record is 123,000 departing passengers - set on July 29 last year.

To ease the pressure on the creaking system, a special Games terminal has been built - off limits to regular passengers.

The exclusive terminal is the size of three Olympic swimming pools. It has 31 check-in desks and seven security lanes.

Athletes are expected to depart with more than three bags per person, including outsize sporting equipment.

BAA chief executive Colin Matthews said: “Heathrow is proud of the part we have played in making London 2012 a success. We hope that Olympic athletes, spectators and officials enjoyed a great welcome to London.

“Olympic departures present a fresh challenge with new facilities like the Games terminal being used for the first time. We have been preparing for seven years to deliver a farewell of which the whole country can be proud.”