Passengers face huge disruption due to the public sector strike on Wednesday but many will be entitled to a refund.

Travellers have been warned to expect huge queues because of action by immigration and passport officers.

Delays at Heathrow could last as long as 12 hours, and airlines have been warned by BAA, which runs many UK airports, of mass cancellations of departing aircraft.

If you're due to fly on Wednesday, check with your airline before going to the airport.

Below we round up your rights if you're affected.

Package holiday bookings

You will either be offered alternative transport (whether you're abroad or still in the UK) or an alternative holiday.

If still in the UK and the alternative holiday is unsuitable, you'll be refunded all elements of your package.

How to claim/get assistance. If in the UK, contact your tour operator or travel agent. If overseas, contact your travel agent or rep.

DIY holidays, where you've booked elements separately

You should get a refund or an alternative flight, under EU regulations...

  • If your flight is cancelled or delayed by over five hours. Airlines must offer you a full refund within seven days of any unused ticket or, if the flight is cancelled, allow you to rebook. If you cannot get to your destination, you'll also get the return leg refunded.

    If you booked your outward and return legs separately, and your return flight goes ahead, but you were unable to reach your destination, it's more complicated. You should get a refund for the return trip as long as both flights are booked with the same carrier, but you're at the mercy of your airline. You may not get a refund if you booked with different airlines.

  • If taking a connecting flight. If you've already made part of your journey, and the next leg is cancelled, you are entitled to your money back within seven days for any unused flights and a free flight back to your departure point.

  • How to claim a refund/rebook. Contact your airline. Many airline websites explain the refund or rebooking process. If unsure, call.

Will I get costs reimbursed while I wait for my flight?

You are entitled to meals and overnight accommodation for long delays. You are also entitled to transport between the airport and your hotel plus up to two phone calls.

However, this only applies while you have an active booking so if you cancel a flight you lose these rights.

How to claim. If your airline provides these for you, there is nothing to claim. If not, keep receipts and claim in writing from your carrier when home.

Will I get extra compensation from the airline?

If the airline is not at fault, as in this case, it only has to refund your ticket and cover any expenses – nothing else.

What about hotels and car hire?

You may have paid for other parts of your holiday in advance, as well as flights or a package. These may include accommodation, car hire or other activities.

Many of these may be refundable so contact the service provider to check. If you can't get your money back, see below.

Will travel insurance pay out?

As your airline is usually responsible for refunding the cost of travel or costs while waiting to fly, travel insurance will primarily kick-in to cover non-airline losses, such as non-refundable hotel bookings.

However, some policies may also pay-out a fixed sum for delay or cancellation even where you get your money back from an airline.

In order for travel insurance to be valid for this week's strike, you must meet two conditions:

  • The insurance must cover strike action or travel disruption. Many policies do not cover this. You often have to buy premium cover or purchase a special add-on.

  • You must have bought insurance before you knew of the event as insurance only covers unknown events. The issue is when companies consider you knew of the strike. Check with your insurer for its cut-off date. Insurers Aviva and Direct Line, for instance, say all policies bought after 14 September, when the strike date was announced, will not cover this industrial action.

If your flight is cancelled and you do not travel, insurers will usually refund your premium if you took out single trip travel insurance.

Card company refunds

If you paid for your holiday on a credit card, the plastic provider is jointly liable by law with the travel company if it breaks its contract where the cost is £100 or more. However, in this case, it's unlikely you will be able to, or need to, use this protection.

Visa and Mastercard also offer a similar guarantee, which would cover debit card payments. Again, it's unlikely you would be able to use this.

This is because your airline should cover flying expenses, while if you cannot get to your destination and therefore cannot stay in a pre-booked hotel or use a pre-booked car hire agreement, that company has done nothing wrong so you wouldn't be protected when paying by plastic.