By Joe Lynam
Business correspondent, BBC News
Film-maker Richard Curtis is the man behind the celebrity campaign
They've had it in the ear from the politicians and the public but now bankers are bracing themselves for an attack from celebrities.
Some of the world's top A-listers are to call for a new tax on banks only days after announcing near record profits and bonuses.
The celebrities - none of whom have yet been formally confirmed - are set to front a worldwide campaign by some of the largest aid groups in calling on banks to pay a new levy of 0.005% on the value of every transaction that they make on international markets.
The celebrities are working with a group of high profile aid organisations, including the Unicef, Oxfam and Cafod, with the stated aim of "re-writing the contract between bankers and ordinary people", creating a so-called "Robin Hood" tax.
If such a charge were to be levied on banks, the charities behind the campaign believe it could raise $175bn (£105bn; 122bn) for worthwhile causes.
The campaign, which is expected to be launched next month, is just the latest to be orchestrated by Richard Curtis - the film-maker behind Notting Hill and Love Actually.
He was also behind the Make Poverty History campaign in the early Noughties.
The charities hopes to persuade stars to wear T-shirts with the words 'LO.OO5E CHANGE' on them.
The group behind the campaign says half the money raised would be spent on home projects including helping to pay for the banking bail-out and the resulting recession.
The rest of the money would be shared with overseas aid budgets and climate change projects.
Oxfam admits that a transaction tax would need global agreement, which would be difficult.
But it urged Britain to proceed unilaterally even without a worldwide deal.
The UK government and Oxfam, who are closely aligned for much of this issue, differ when it comes to unilateralism.
US banking reforms
Gordon Brown, who first suggested the idea of a transaction tax at last November's G20 summit of finance ministers in Scotland, says that there could only be a tax if it was agreed and implemented around the world.
Barack Obama's radical banking overhaul could scupper the plans
At the time, Mr Brown's proposal - whilst welcomed by most G20 countries - was all but dismissed by the US and Canada.
But things have changed quite a bit since last autumn.
The Canadians may still be resisting any transaction tax but the American position is almost unrecognisable.
US President Barack Obama's radical call on Thursday, for the effective break-up of America's largest banks, may lead to dramatic changes to the banking environment all over the world.
Ironically, this could damage the charities' plan for a global transaction tax, as slimmed down banks may not be willing or able to trade as they have done before.
It could take months before we know what the international banking system will look like after the kind of fundamental overhaul many senior politicians are calling for.
In the meantime, the publicity train for a transaction tax will roll on - coming soon to a cinema, advertising billboard or website near you.