Greece has said no to an austerity-heavy deal with its international creditors, the country's finance minister, Yanis Varoufakis has walked away and Europe's leaders are scrambling to communicate ahead of tomorrow's meeting of eurozone leaders and finance ministers.

What now?

The next few days are crucial. German Chancellor Angela Merkel and French President Francois Hollande will meet in Paris today, and on Tuesday evening eurozone leaders and finance ministers will hold an emergency summit.

Greece is emboldened and wants to return to the negotiating table, believing a more favourable bailout deal could be reached in 48 hours.

But some of Europe's top politicians, such as Germany’s deputy chancellor, have already said it’s "barely conceivable" and that Greece has now "torn down the last bridges."

Could a 'Grexit' really happen?

No country has ever left the euro currency but it’s now a real possibility - especially if creditors, such as the European Central Bank, refuse to resume talks.

That said - there is no actual mechanism to expel / extract a country from the monetary union.

With no new bailout agreed, Greece's banks could run out of money within days, cash machines are currently rationed to €60 a day - and they are in danger of running dry.

Economists suggest that it could then have to issue IOUs to pay pensions and public sector wages, or leave the euro altogether and return to the drachma to keep the economy afloat.

We should learn today if the ECB is willing to provide emergency funding to Greece's banks.

Would a Greek exit be a bad thing?

It sets a dangerous precedent and undermines the longterm stability of the bloc, but the fact that Greece has ended up going so far astray highlights some of the underlying weaknesses, and economic imbalances built into the euro project.

Having its own currency would offer advantages to Greece, it would make exports cheaper and offer value to tourists, but the economic meltdown that would be likely to happen if it left the euro would probably be more damaging than any benefits that it would offer.

Despite the No vote, opinion polls still show more than 70 percent of Greeks want to keep the euro.

What are the Irish implications?

Ireland's government parties have alined themselves with the most hardline conservative forces in the Union.

If Greece's defiance ends in an economic disaster / messy eurozone exit, Fine Gael and Labour will use it to fuel their safe pair of hands, "we got the economy back on-track" narrative heading into the next election.

Michael Noonan released a brief statement last night committing to work towards a solution to the debt crisis.

The government's stance could be softening, European Affairs Minister, Dara Murphy said this morning that Ireland could support debt relief for Greece.

But if Syriza can secure a significant debt write-down this will give a bounce to Sinn Fein, who have aligned themselves with the Greek party.

The AAA and other leftist independents will also be buoyed by a positive deal for Syriza, they are are likely to attack Sinn Fein's social credentials in the next election and try to establish themselves as the main opposition group.

What’s the worst-case scenario for Greece?

The economy has shrunk by 25 percent since 2008 and it's been suggested the consequences of a euro exit could see a further initial significant contraction.

Greece's massive tourist industry could be hit hard as travellers shy away from the country, leading to more job losses.

One in four people in the country is already unemployed - among under-25s it’s nearly 52 percent.

A snowball effect from all the above could also see hyper-inflation, with everyday products rapidly increasing in value - and possibly mass demonstrations on the streets.

What about going on holiday?

The Greek tourist board and the UK's Foreign Office are advising travellers not to rely solely on credit cards and cash machines.

They should carry three to five days' worth of euro notes and coins.

If Greece ditched the euro, Visa says business should continue as usual: "When a country exits a currency, we take steps to remove the old and add the new currency into our systems, meaning that the system for processing payments is still in place."

Additional reporting by IRN