The City of London Corporation has launched an annual competition for a member of the public to win the opportunity to take the controls of Tower Bridge, stop the traffic and raise the bascules for a boat to pass through.
The 'guest bridge driver' will be supervised by a senior technical officer, who will guide him or her through the procedure, which involves making a series of public announcements and using a joystick and a sequence of buttons to close, unlock, raise, lower, lock and reopen the bridge.
Afterwards, he or she will be presented with a commemorative certificate in the control cabin, before being offered a tour of the Tower Bridge Exhibition, as well as the chance to visit the underground bascule chamber and the fifth-level turrets, neither of which are open to the public. As they leave Tower Bridge, they will be given a bottle of champagne.
Applicants can enter the prize draw by answering a question about Tower Bridge or the Square Mile on the bridge's website. The answer can be found by visiting the Tower Bridge Exhibition or by exploring the bridge's website and the City of London Corporation's 'Visit the City' website.
The winner will be chosen by selecting a random number from the total number of entries emailed to firstname.lastname@example.org
Lord Mayor of London Michael Bear will make the first draw in April.
"It may take around eight minutes to perform a bridge lift, but the competition winners' memory of taking the controls of this historic landmark will last a lifetime," says bridge master Eric Sutherns MBE.
"As well as being a privilege, you feel a real sense of responsibility. The controls in your hands are lifting over 2,000 tonnes of Victorian ironwork and bringing part of the city's traffic to a standstill.
"I hope that people will enjoy entering the prize draw, and my colleagues and I look forward to welcoming the lucky winners and their guests to the control room for their briefing and bridge lift."
Well-known people who have opened Tower Bridge include Sir Terry Wogan, Will Self and Simon Hoggart.
Matthew Parris, The Times columnist and former Conservative MP, who was invited to open the Bridge in November 2008 to fulfil a life-long ambition, said: "I'd always wondered what it would be like to open Tower Bridge, so when the City of London Corporation invited me to do so, I happily accepted. I imagined that my participation would be a token thing – but there I was, actually operating the bridge!
"It was such a thrill to stand in the control room, with the lever in my hand, and watch as the wrought iron gates closed and the bascules rose up. I hope the winners enjoy their bridge lifts as much as I did."
Any vessel with a mast of 30ft or more is required to pre-book an opening to enable it to pass under Tower Bridge, for which the two bascules can be raised to an angle of up to 87 degrees, using massive counterweights in an underground chamber.
Tower Bridge has not been raised for several months whilst the bascules have been repainted. The next scheduled bridge lift is on Saturday 9 April.