Ryanair and easyJet have been rapped by a watchdog for "misleading" holiday makers in the latest battle of the budget airlines.

Three advertisements, published in national newspapers in the UK, were banned after they were found to have made false claims relating to cheap flights.

While England-based easyJet was slammed for the bold statement, "We charge you less", its arch-rival - who complained to the British Advertising Standards Authority (ASA)- was itself pulled up over two separate promotions.

The first easyJet offer, headlined "The new shape of business travel", sparked anger from its competitor who insisted its own fares were cheaper on a number of routes. Ryanair's objection was upheld and easyJet was ordered not to run the advertisement again in its current form.

However, Michael O'Leary's carrier did not escape unscathed after the watchdog ordered it to pull two of its own promotions. One, featuring a bikini-clad woman holding a cocktail and the text "Book to the sun now!", offered flights from £8.

However, a close examination revealed customers were limited to destinations with maximum temperatures of 11C. In some places, the mercury dropped as low as 0C during the promotional period.

"We considered that the average consumer would infer from the claim 'Book to the sun now' and the image of the woman sunbathing, in a bikini, with a cocktail, that the promotion included fares to destinations warm enough to sunbathe in swimwear during the promotional period," the ASA added. "Because we understood this was not the case, we concluded that the ad was misleading."

The second Ryanair advertisement, which offered flights to Dublin for £27.99, sparked complaints on the grounds that it was apparently impossible to book a flight at the price quoted because of an additional £6 online check-in fee. Ryanair was unable to "clarify adequately" how the promotional fare could be achieved, the watchdog said.

Accepting the watchdog's decision, a spokesman for easyJet said: "EasyJet is happy to comply with the ASA's ruling on this technical point. We were surprised to hear that Ryanair had concerns over this advertisement as it is the first time that they have ever expressed any interest in the business traveller."

A spokesman for Ryanair said: "Ryanair has noted the ruling."