A Ryanair advertising campaign that criticised Gordon Brown's increase in air passenger duty has been censured by the advertising watchdog.

Ryanair ran a series of four national press ads, using pictures of the then chancellor to complain about the increased tax rate.

The ads ran with headlines such as "The great plane robber", "Greedy Gordon's shock confession" and "Welcome to Britain: this is a stick up!", and attacked claims that the tax increase was to help the environment.

The airline claimed that the government would make more than £1bn from the air passenger duty increase and that Treasury had no plans to invest any of the revenue into environmental programmes.

One ad featured the Pope saying "Even I can't absolve you of that sin" to Gordon Brown after he has said he will be "nicking" £1bn "from tourists".

The Advertising Standards Authority received a total of 48 complaints.

The vast majority - more than 30, including one from AirportWatch - challenged Ryanair's claim that "aviation accounts for just 2% of CO2 emissions".

Ten complainants objected to the use of the Pope as being offensive to Christians, while several complainants challenged the claim that "UK tourists will pay £1bn more in taxes".

And two challenged the Ryanair claim that no money was going to environmental projects.

The Advertising Standards Authority agreed with Ryanair's defence of the £1bn figure based on HM Revenue and Customs figures.

However, it ruled against the airline on two other claims. It ruled that Ryanair was misleading over the 2% claim because it failed to be clear about the basis of its claim, even though there was no agreed method for attributing international flight emissions to specific countries.

The ad watchdog upheld the complaint against the claim that "not a penny spent on the environment" because the government had said that some revenues would go toward "environmental measures and in increasing public transport".

The ASA dismissed complaints that the Pope ad was denigratory to the pontiff or to the Catholic religion.

The Times, which only received one complaint about the ad, said it was unlikely to cause widespread offence and that the style of the image featuring the Pope was very similar to that used by Private Eye.

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