More than a million British holidaymakers will be heading to Greece this summer, and as the crisis unfolds many will naturally be feeling nervous about how it could affect them.
Greek banks are shut and there are restrictions on how much Greeks can withdraw from banks - known as capital controls.
But tourists' credit and bank cards issued abroad can be used at functioning cash machines freely - subject to queues and the amount of cash in them.
Here is the latest advice from travel experts.
How much cash should I bring?
Travel advice from the Foreign Office says that while banks are closed in Greece, tourists should make sure they take sufficient euros in cash "to cover the duration of your stay, emergencies, unforeseen circumstances and any unexpected delays".
"You should take appropriate security precautions against theft. There are currently no restrictions on taking unspent euros out of Greece at the end of your stay," it adds.
Andrew Brown, from Post Office Travel Money, says couples spend an average of around £500 in cash on a fortnight's holiday - on things like meals out, local trips and coffees. For a family, that figure is £700.
That does not include accommodation, and the advice is to contact your hotel, internet booking company or villa owner beforehand, to see whether it is possible to pay in advance in sterling.
Once there, visitors are advised to use safes and deposit boxes to store cash, and to split money between family members.
The Foreign Office also updated its travel advice following the recent vote rejecting the terms of an international bailout, saying that "the outcome of this referendum may lead to an increase in demonstrations across the country".
Is this cash covered by travel insurance?
Insurance group Aviva has doubled the cover for stolen money for people travelling to Greece having bought its travel insurance.
The standard amount of lost cash covered goes up to £600 from £300 per adult, so a couple would have £1,200 of cash protected.
The insurer said it wanted customers who were carrying more cash to Greece to be confident that they were covered if the money were lost or stolen.
Other insurers have followed suit, adding to the cash protection available but stressing the need for travellers to take care of their cash.
Travel association Abta has updated its advice, saying: "Holidaymakers should check how much cash their travel insurance policy covers them for and should take appropriate security precautions against theft such as using their hotel safe or splitting cash up between their party."
Will I be able to use credit or debit cards in restaurants and shops? If so, will there be a limit on how much I can spend?
The new limits on withdrawals from ATMs by those with Greek bank accounts do not apply to tourists, but there is concern that cash machines will be empty.
All cards currently accepted, such as MasterCard and Visa, will continue to work as normal.
Previous experience suggests that smaller shops and restaurants may be reluctant to accept credit and debit cards, preferring customers to pay in cash instead. That is because they might find it difficult to get hold of cash from their own accounts.
What about my car rental?
There have been reports of car rental providers asking for cash, rather than vouchers, although this has not been confirmed by the companies.
As with accommodation, it may be a good idea to check in advance.
Will the ATMs have enough money in them?
It depends on where you are, but it is certainly a risk. As a general rule, ATMs are more likely to run out of cash on the Greek islands than on the mainland.
Will I be able to use pre-paid currency cards or travellers' cheques?
Currency cards can be loaded with a foreign currency at a pre-agreed exchange rate and used in shops or at ATMs whilst abroad without incurring commissions or transaction fees.
Again, smaller shops might start to be reluctant to take them, although they are still fully functioning.
Travellers' cheques are not widely accepted so it would not be advisable to rely on them as the only source of payment.
Western Union, the world's largest money transfer company, now allows transfers into the country but the withdrawal limits from Greek bank accounts still apply.
If Greece were to leave the eurozone, how long would euros be valid for?
Post Office Travel Money's Andrew Brown says holidaymakers should not panic if Greece leaves the eurozone. If this happened, it would take around 18 months for the Greek drachma to be re-introduced, during which time the euro would continue to be the legal currency.
A Visa spokesman added: "While there are some issues that would be outside Visa's control, we would work with all relevant parties to help ensure a swift transition to a new currency with the minimum possible disruption to consumers and retailers."
Will my insurance policy cover my losses if I decide to cancel?
The advice from the Association of British Insurers (ABI) is always to check the latest Foreign and Commonwealth Office advice. An ABI spokesperson said: "Those who have their summer holidays planned in Greece remain covered by their travel insurance, in line with the terms and conditions."
She said that would only change if the FCO changed its stance and decided to advise against all travel. In that case, travellers would not be covered if they still decided to go, but they would be entitled to a refund, either from their travel agent or tour operator, or their insurance company.
The good news is that Greece continues to be a great bet for bargain hunters, according to the latest Post Office Travel Money resort research. The strength of sterling means families changing £500 into euros will get the equivalent of £65 more to spend compared with a year ago.
Prices in resort islands such as Crete and Corfu are down by more than 13% this year anyway - which means a meal in Crete with drinks will be almost £6 cheaper, and a bottle of suncream will be £3.32 less than it was last year.
The price of holidays in Greece has also dropped.
This may be why UK package holiday bookings to Greece were up 2% in the year to 27 June, compared with the previous year, according to GfK Ascent's Leisure Travel Monitor.
However, the Greek Tourism Confederation said that, following the referendum announcement, it had recorded a 30% drop in last-minute bookings.