Travel on a Tuesday if you want the cheapest flights

For a cheap flight to Europe, fly on a Tuesday: that is the conclusion of a Which? Travel study, published today. The magazine studied fares on more than 1,000 flights departing next month on three key European routes.

Flying with easyJet from Gatwick to Alicante on a Tuesday saved, on average, at least 25 per cent compared with the Friday fare – a typical saving of £28.

The priciest day depended on the airline. For BA's Heathrow-Barcelona flight, Fridays and Saturdays were most expensive. On Ryanair's Stansted-Dublin route, Sunday departures had by far the highest average fares. Inbound fares were highest at weekends, with Sunday arrivals most expensive on all three carriers.

The time of day was also relevant. Six out of seven of the cheapest BA fares were found outbound on the first two flights of the day, and the same proportion inbound on the last two flights. This is because there are few transfer opportunities to and from these flights at Heath-row Terminal Five, and therefore passenger loads tend to be lower.

By contrast, on easyJet – a "point-to-point" airline that does not offer connections – morning flights as early as 5.45am were the most expensive. Richard Lloyd, executive director of Which?, said: "People can save a significant sum of money if they shop around and can be flexible, changing the day or time they choose to travel."

Tuesdays also offer the best chance of an adjacent empty seat. The reason the 9/11 attacks took place on a Tuesday was because the terrorists knew that was the day of the week with the lowest average "load factor" on US domestic flights: typically 50 per cent or less, meaning there were fewer passengers to overpower.

The "fly on Tuesday" rule does not apply after bank holiday weekends. Yesterday, the only available flight The Independent could find from Malaga to the London area for today was a single seat at €1,242 (£984) one way on British Airways.