So: Angela Merkel proposes a Greek referendum on the euro, David Cameron says the forthcoming election there is the equivalent of a referendum. But as ancient Greeks knew, what is needed at this point is an ostracism.
An ostrakon (pl. ostraka) was a piece of broken pottery. It cost nothing (unlike papyrus) and was widely available. On it, Athenian citizens wrote the name of the individual whom they wanted removed from the political arena in Athens and sent into honourable exile for ten years.
It worked like this. Once a year, Athenian citizens in Assembly were asked if they wanted to hold an ostracism. The reason for it can be understood only in the context of real democracy, i.e. where citizens made all the decisions after listening to the arguments for this or that course of action put forward in the Assembly. If two diametrically opposed courses of action were so evenly supported that deadlock ensued, it made sense to remove one of the speakers. So the purpose of ostracism was essentially administrative, to clear the air. It could always be revoked.
If the Assembly voted for an ostracism, it was staged two months later. This gave plenty of time for Athenians to debate among themselves the pros and cons of getting rid of one or other turbulent politician. On the day of the ostracism, there was no debate in the Assembly on the matter; each citizen simply scratched on an ostrakon the name of his chosen candidate, and as long as 6,000 ostraka were cast, the man with the most votes was given the order of the pot.