Q&A: Will Greece exit the euro?

"It would be a mistake to say they can never leave," says Simon Tilford, chief economist at the Centre for European Reform. Tilford said an orderly transition could be planned with temporary backing from the rest of the eurozone to ensure that there is no panicked withdrawal of Greek investments. "If you argue that it can never happen you must be arguing that Greece must default on its debts in the eurozone and remain in the currency, that's possible and it might be the most likely outcome. But I think it would be mistake to say they can never leave. It might be possible to bring it all off without the cataclysmic damage that some are pointing to It all depends on how it's handled. That said it's never going to be good. You don't have sovereign default without an awful lot of problems."