Accidental exits, vulture funds: what's at stake in a 'Grexit'?

The arduous negotiations between the EU and Greece over a temporary loan to resolve Athens? bailout crisis has reawakened fears of a "Grexit", or Greek exit from the single currency bloc.

Here are in three questions some of the issues at stake:

The European Commission insists that a country cannot leave the common currency, because there is no provision for it in the EUs treaties. So once youre in, youre in.

"Even if there is no clause" permitting a country to quit the eurozone, "it is still possible to find a legal construct" which would allow it, according to Janis Emmanouilidis, from the European Policy Centre.

Leaving the euro might have to be tied to an exit from the European Union.

If Athens fails to fulfil its bailout obligations, the eurozone and European Central Bank (ECB) have the means to push the country out by putting the squeeze on its lenders and forcing it to introduce a parallel currency.

That drastic measure is not on the cards for now, with the ECB Wednesday extending and increasing for two weeks the amount of emergency liquidity available to Greek banks.

The Jacques Delors institute in Berlin has warned of two other possible scenarios, in the first of which Greece introduces a parallel currency to enable it to fulfil its pledges to end austerity and ease the burden on the poor.

But most Greeks are in favour of sticking with the euro and the radical left ruling party SYRIZA has never hinted it would contemplate such a dramatic move.

In the second scenario, Greece exits the euro "by accident", because a failure to reach a deal or even just a pause in negotiations sparks a sudden bank run, forcing the Greek government to introduce a parallel currency.

Greece's Finance Minister Yanis...