Richard Curtis and Bill Nighy team up in new film urging Tobin tax on bankers

It could be a plot from one of his feelgood movies. Against a snowy London backdrop, something perennially ignored and unloved finds the attention it craves against all odds. Only this time, director Richard Curtis is hoping to sprinkle his stardust on an arcane bank tax rather than a lovelorn English fop.

Britain's most successful comedy writer is aiming to tap into the public's fury at how bankers are scooping huge bonuses while the rest of us suffer pay freezes by spearheading the launch of a campaign demanding the introduction of a "Robin Hood tax" on financial institutions.

Harnessing YouTube, Facebook and celebrity endorsements, Curtis has taken what was once regarded as a naive pipedream to tax a slice of every financial trade and given it a makeover. The Tobin Tax, named after the American economist who first suggested the idea, is now rebranded the Robin Hood tax.

Curtis's involvement will recall how the Four Weddings and a Funeral writer marshalled both the Drop the Debt and Make Poverty History campaigns in the run-up to the Gleneagles G8 meeting in 2005.

The man responsible for a string of top grossing films, from Four Weddings and a Funeral to Love Actually, has been crucial in cementing agreement between groups as diverse as Barnardos, the RSPB, the Salvation Army and the TUC. He also attended meetings with senior Labour and Conservative figures along with campaigners to lobby for its introduction.

Curtis has also roped in his long-time collaborator Bill Nighy to star in a short film where he plays a senior banking executive who grows increasingly uncomfortable when quizzed about whether such a tax could work and how much it would raise. The film, directed by Curtis, is being premiered on guardian.co.uk and YouTube. Bono's development group, the One campaign, has also lent its weight and is expected to unveil a host of new supporters in coming months.

The powerful new coalition of domestic and overseas charities, unions and church groups argue that a Robin Hood tax could generate $700bn (£450bn) worldwide. The tax would see 0.05% levied on each bank trade ranging from shares to foreign exchange and derivatives, creating a cash pile to be spent on measures to combat domestic and international poverty as well as fight climate change.

A slick advertising campaign by Empire Design features slogans such as: "This is the first tax you'll be in favour of" and "Small change for the banks, huge changes for the world".

"As a result of the financial crisis there are suggestions there's no money to fight climate change, there's talk about cuts to schools and there's concern where the money will come from to meet the Millennium Development goals," Curtis said. "There is money in the banking system. There has been a huge expansion in banking activities. And yet we may all have to pay more VAT on everything we buy.

"I understand it is complicated and contentious and there are other ideas on the table, but what we are trying to create is an instinctive link between fixing banks and the huge challenges facing people on this planet. Do we drop promises on child poverty or do we tax the British public? Or do we work with banks to find a solution?"

The tax has long been demanded by campaigners but brushed aside by politicians and bankers as an impossible dream. Buoyed by the support of the UN, Gordon Brown last year became the first global leader to publicly call for its introduction as a way for banks to compensate society for causing the global financial crisis.

The campaign has already lived up to its outlaw image. In the early hours of Tuesday morning, the question "Do you want to be part of the world's biggest bank job?" was projected onto the Bank of England. From tomorrow, campaigners will ask Facebook networkers to don green Robin Hood style facemasks as a show of support.

For and against

Pros

The main argument in favour of a financial transaction tax is that it would raise a large sum of money painlessly, and would help to limit the sort of speculative attacks being seen on vulnerable countries such as Greece and Spain. Because turnover in the global financial markets is so enormous, even a tax levied at 0.05% on every trade could raise $400bn (£255bn) a year – enough to double foreign aid, provide $100bn a year for poor countries to adapt to climate change, and leave $100bn over for rich countries to reduce their deficits. Politically, a Tobin tax has become more attractive as governments have woken up to public anger at the banks deemed responsible for the crisis, and to the budgetary cost of clearing up the mess. Those in favour say it is only fair the banks should pay.

Cons

There are three main arguments against a Tobin tax. The first is that it would only work if all the major economies adopted it, something that is unlikely given longstanding opposition from the US. The second is that a transaction tax would impede the efficient working of markets and add to business costs, which would be passed on to consumers. Finally, there is the question of whether a tax at such a low rate would be effective in deterring speculation – the economist James Tobin always thought a far higher tax would be needed to throw "sand in the wheels" of finance.

Larry Elliott

Experts' view

Joseph Stiglitz, professor of economics at Columbia University: "A tax structure that does not reward short-term, very speculative gains would be good. If you were investing for a year or five years or 10 years it would be a small tax but if you were holding it for just one minute it becomes a very high tax. The important question is implementability. It's designed to tackle high frequency activity for which it is hard to find any societal benefit. The only question is, can it be effectively implemented? Will it be circumvented? There's a growing consensus it can be implemented, if not perfectly, effectively enough to make a difference."

Ann Pettifor, fellow, New Economics Foundation: "The proposed currency transaction tax (CTT) represents the tiniest grain of sand in the wheels of global, mobile capital, and places very little restraint on the movement of international capital. For that reason CTT will be welcomed, ultimately, by international financial institutions. The proposal lacks a framework of democratic, accountable governance for the disbursement of funds collected under a CTT scheme. NGOs and treasuries are debating whether funds should go, for example, to national treasuries; to the Global Fund to fight Aids, TB and Malaria, or to the UN for mitigation and adaption to climate change. Until disbursement and distribution of CTT revenues are accounted for in a democratic, fair, and transparent way, the CTT will be vulnerable to attack."

David Kern, chief economist at the British Chambers of Commerce: "It may have potential. I'm not sure it's the most appropriate thing. I think the main argument against it is that it's most unlikely to be implemented globally. If a tax could be applied it would have beneficial effects … My reservation is that for the UK to engage in this unilaterally would be a very dangerous thing to do because it would destroy the country's financial sector. People and businesses would migrate to other places. If the US and big European countries implemented it as well then it would not harm our financial sector as much."