Thousands of passengers face travel chaos as drifting ash from an Icelandic volcanic eruption grounds hundreds of flights.
The ash has already hit Scotland and is set to continue spreading to Wales, northern England and Northern Ireland by midday today, causing further disruption to air travel.
Several airlines, including BA, KLM and Easyjet, have suspended services in and out of Scotland and further cancellations are expected later today. The Met Office says changing weather conditions make it hard to predict exactly the pattern the ash will take.
Iceland's Grimsvotn volcano began erupting on Saturday, just over a year after volcanic ash from the eruption of the country's Eyjafjallajokull volcano caused major travel disruption to holidaymakers travelling to or from Europe.
If you are travelling on a package holiday, covered by Air Travel Organisers' Licensing (ATOL), you should contact your tour operator for advice. It is the operator's job to cover all costs should air space be disrupted. Travellers still in the UK are entitled to refunds or transfers, and those overseas will be kept in accommodation at the expense of the tour operator.
If you have arranged independent travel it will be up to you to contact the airline or hotel company directly to enquire about refunds, changes or cancellations. In this instance you should check your travel insurance policy, especially looking out for natural disaster and weather-related causes.
Bob Atkinson, spokesperson at travelsupermarket.com, says today's news will bring the same uncertainty experienced in April 2010.
"Travellers are urged not to do anything without speaking to their airline or tour operator first, checking its websites for further information," he adds.
The Foreign Office is advising passengers to remain in regular contact with their travel agent or airline for the latest news on the status of flights and bookings. Exact details of flight cancellations can be found on airline websites, or by checking the foreign office website.
Will your travel insurance pay out for ash cloud disruptions?
Single and annual trip insurance policies vary widely in how they treat ash cloud-related disruption, according to Defaqto. If a holiday is completely cancelled as a result of the disruption, 40% of single trip policies provide £5,000 cover or more for the cost of the holiday, 14% offer cover of less than £2,000 and 12% provide no cover.
While 51% of annual trip policies provide £5,000 or more towards the cost of the holiday, 14% provide cover of less than £2,000 and 1% of policies offer no cover at all for this.
You will need to check if the policy considers the ash cloud to be a weather-related event and therefore provides cover at all, or whether the policy expressly excludes ash cloud events. If the policy does cover this, you will need to check the level of cover it provides.
Mike Powell, spokesperson for Defaqto, says: "The devil is in the detail. If holidaymakers are unsure, it is worth speaking to their insurance provider to get clarity on how they would treat any claims relating to the affects of the ash cloud."