The Mayor's Senior Advisor for Volunteering, Charities and Sponsorship, Veronica Wadley, said:
"2012 has been an extraordinary year for London and the achievement of hosting the Games has shown what a terrific welcome we can give visitors. With the help of the Team London Ambassadors and other volunteering programmes, we want to build on the city's reputation for being able to deliver the most fantastic place in the world to visit."
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Londoners who have received new electronic gadgets for Christmas are being advised to take simple steps to protect them from thieves.
The Boxing Day sales got off to a flying start with shops reporting a surge in business during the first hour of trading.
Bus strikes are planned for Monday 29 December and Monday 5 January.