The advertising watchdog has criticised British Airways for not providing enough flights at the discounted prices stated in an ad campaign, after receiving a complaint from rival airline Easyjet.

BA launched a national press, poster and internet push, using the strapline "Cutting prices, not corners", to a variety of European destinations including Turin, Marseille and Prague.

The airline said that the cheapest prices - marked as "from" in the advertising - applied to outbound seats during the period of the promotion from April 20 2006 to March 31 2007.

BA argued that it had ensured there was "more than 10% availability" at the cheapest flights on those three routes - the ones specifically complained about by easyJet.

The Advertising Standards Authority examined spreadsheets provided by BA proving this.

However, the ASA found that 10% availability was not guaranteed across the whole period of the promotion.

There were periods of high availability of the cheapest tickets and periods when there few, or even none, of them available.

The ASA cleared BA over its press and poster campaign promoting flights to Turin and Marseille.

In the case of the internet ad campaign, for Prague, the ASA ruled against BA after finding that most of the cheapest seats to the Czech capital were offered on flights more than six months after the ad appeared with little, or no, availability before.

The ASA said that the claim "Prague one-way from £29" was therefore misleading because "BA needed to show that at least 10% of seats were available at the 'from' price throughout a reasonable spread of the promotional period."

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