THE campaign against Britain’s air passenger duty (APD) has gathered 40,000 new supporters since Virgin boss Sir Richard Branson threw his weight behind it last week.

Sir Richard launched a storm of messages on British MPs with a Twitter message railing against the tax on flights leaving the UK.

APD rose by eight per cent this year, with the amount paid dependent on the distance travelled.

Passengers going short distances will pay £13 ($1,800), but those travelling over 4,000 miles — to Jamaica, for example — will be taxed up to £92 ($12,700).

A Fair Tax on Flying, the lobby group behind the campaign, says the APD is the highest in the world, with Britons paying almost 400 per cent more than most Europeans do.

The group began encouraging people to write to their members of parliament after the increase was quietly announced in the March budget.

The number of emails grew to 55,000 after Twitter users sent them en masse on Friday in one of the biggest social networking campaigns to date.

“The Branson effect”, as the group calls it, started after the airline mogul publicly supported the campaign.

Sir Richard’s Virgin Atlantic began adding links to the group’s website on its electronic tickets earlier this month.

“This suffocating tax has rocketed way out of control,” Sir Richard said in Cancun, Mexico. “Years of aboveinflation increases have hit passengers hard, are hitting the economy hard and are impeding our recovery from the recession.

“It is obscene for the Treasury to be taking £10 million every day from visitors and British holidaymakers alike”.

Hotels.com President David Roche said the tax “deals a blow to Britain’s tourist sector”, particularly in an Olympic year.

Visitors for the Games will be charged APD on their return trips.

The Caribbean Tourism Organisation (CTO) has called for Britain to reduce the APD since the increased tax has resulted in fewer visits to the region by UK tourists.

CTO Chairman Ricky Skerritt said after the announcement that it was “a slap in the face for all Caribbean people”.

“The Caribbean is the most tourism-dependent region of the world,” he said. “The British government’s decision totally ignores the negative effect that the APD is having on our economies and the Caribbean’s business partners in the UK travel industry.”

London defended the increase, noting that APD was frozen last year.

The tax is expected to increase again in 2013 to match inflation.

The APD has been described as a green tax, designed to protect the environment by deterring people from flying.

However, in announcing that the tax would take in £2.6 billion, up from 2.4 billion last year, Britain’s Treasury recently admitted that it was primarily a revenue raiser.