David Cameron has been accused of joining the "unaccountable clique of Davos men" after he attended the secretive Bilderberg group meeting at the luxury Grove hotel in Watford, a move that raised questions about his pledge to lead Britain's most transparent government.

Douglas Carswell, the Tory MP who campaigns for transparency in government, said the prime minister was taking part in a "cliche fest" whose participants had helped crash the global financial system. Davos is the town in Switzerland that hosts an annual meeting of global political and business leaders.

Cameron came under fire after Downing Street said it was acting in an open manner by publicising his attendance at the annual Bilderbergmeeting in advance. The prime minister's spokesman, who said heads of government of countries hosting the annual Bilderberg meeting were usually invited to attend, said it would be a private event and that civil servants would not accompany Cameron.

Ministers are usually expected to be accompanied by civil service note-takers when they meet business leaders. Henri de Castries, the chairman and CEO of Axa Group, is the Bilderberg chairman.

The prime minister's spokesman said: "He will participate in a discussion around domestic and global economic issues. He feels it is an opportunity to discuss economic issues with senior ministers, businesspeople and academics."

Downing Street said it would not publicise any details of the meeting: "It is a private meeting so we are not going to go into any further details."

"On a wider point the prime minister has always been clear about the importance of transparency which is why this government has taken a number of steps in terms of publishing more data, more information about meetings."

Carswell told the Guardian: "Given the dreadful state that most European countries are in – and given the appalling public policy failures that landed us in this mess – you would have thought the least our ruling elite could do is discuss these issues in public. This is only going to add to the idea that we are governed by an unaccountable clique of Davos men.

"I am sure in reality they will be recycling all the cliches you can find in the FT and the Economist. I don't think that great leaders like Margaret Thatcher and Ronald Reagan attended the Bilderberg."

Carswell added that Eurosceptics were likely to be concerned that the prime minister was interested in hearing from a group whose steering committee included five prominent European integrationists – the ex-chancellor Kenneth Clarke, the Belgian aristocrat and former European commission vice-president Viscount Étienne Davignon, the former British ambassador to the EU Lord Kerr of Kinlochard, the former Irish EU commissioner Peter Sutherland and the former European Central Bank president Jean-Claude Trichet.

Carswell said: "I am absolutely not a conspiracy theorist but it is striking that the grandees invited to this self-selecting little clique all tend to regurgitate the same failed orthodoxies. It doesn't matter whether it is the same failed orthodoxy of Europeanism or the fallacy that cheap credit and low interest rates can make us rich – they are the same washed-up ideas of the last 20 years. It is a cliche fest."

Cameron and Nick Clegg pledged when they formed the coalition to lead the most transparent government to date. The coalition agreement said: "The government believes that we need to throw open the doors of public bodies, to enable the public to hold politicians and public bodies to account."

The ministerial code, published by the government in September 2010, said ministers' external meetings would be published on a quarterly basis. It says: "Ministers meet many people and organisations and consider a wide range of views as part of the formulation of government policy. Departments will publish, at least quarterly, details of ministers' external meetings."

No 10 said it did not believe that civil servants would accompany the prime minister. It took Downing Street five hours to confirm this. It said that the meeting would be recorded "in the usual way".

Cameron's attendance brings to three the number of British ministers at this year's summit. George Osborne is also attending and Kenneth Clarke is a member of the steering committee. The Bilderberg group says the costs of the meeting are the responsibility of the steering group, whose members include former Barclays chairman Marcus Agius, the CEO of the defence manufacturer EADS, Thomas Enders, and the Goldman Sachs International chairman, Peter Sutherland.

The group says: "There is no detailed agenda, no resolutions are proposed, no votes are taken, and no policy statements are issued." And no-one knows what is going on !