Britain's finance minister, Alistair Darling, has criticised Swiss banking secrecy laws, saying the country needs a more transparent system.
In an interview published on Sunday in the Observer newspaper, Darling said it was intolerable that banking secrecy allowed some people to shelter their wealth from tax, while others had no choice but to pay.
"It's one of the things Switzerland has got to address. If it wants to be part of the international community, it's got to be open," he told the British newspaper.
"People don't know what's going on. That's not good. Indeed, half the many problems we have got now are because people didn't know what was going on."
On Wednesday, British Prime Minister Gordon Brown sounded a call for "the whole of the world to take action" against regulatory and tax havens that had "escaped the regulatory attention" they needed.
The Observer's sister newspaper, the Guardian, reported the following day that Brown was "taking a particular interest in Switzerland" and aimed to clamp down on individuals who avoid tax.
Darling's comments coincide with a meeting in Berlin on Sunday at which European Union leaders backed oversight of the world's financial markets and urged sanctions be drawn up to punish tax havens.
The gathering was meant to prepare the ground for the April G20 summit of developing and developed countries on the economic downturn. The Swiss finance ministry has confirmed that Switzerland has not been invited.