UK airspace was closed for six days
The closure of UK airspace because of the Icelandic volcanic ash cloud cost London more than £100m in lost tourist spending, new figures have claimed.
According to London's mayor and Visit London, about 30,000 overseas visitors arrive by air every day at this time of year, spending £17m in total.
They said last week's flight ban, which lasted six days, cost the city £102m.
Hotel occupancy is down as much as 25%, and theatre, restaurants and shops have all seen a fall in visitors, they said.
A spokeswoman for the mayor said in the first few days of the airspace suspension, an estimated 100,000 visitors remained in London who would otherwise have gone home.
But she said: "Facing uncertainty and dwindling resources, many who remained in the city were simply waiting out their time, worried about when and how they would return to their homes."
She added despite the fact London hotels were initially busy, occupancy rates began to drop as many visitors due to go home found alternative ways to leave the city and were not replaced.
Mayor of London Boris Johnson said: "Coming out of the economic downturn, the last thing the capital's economy needed was all air traffic in and out of the city grounded for a week.
"Tourism is massively important for jobs and growth in the capital."
Colin Stanbridge, chief executive of the London Chamber of Commerce and Industry, said: "Some firms suffered from the reduced footfall on London's streets and others faced disappointed customers, heavy backlogs and costly penalties from being unable to access airfreight services to deliver the three million items sent by London companies every day."
Dame Judith Mayhew Jonas, chairman of New West End Company, which represents 600 retailers, said there had been a drop in footfall in the West End.
Air traffic control body Nats imposed UK flight restrictions amid fears ash from the eruption of the Eyjafjallajokull volcano could damage aircraft engines.
More than 95,000 flights were cancelled across Europe during the six days of disruption, with only a handful of flights taking off and landing at UK airports.
The restrictions were lifted late on Tuesday.