Britons are among "the worst idlers" in the world preferring a "lie-in to hard work", according to group of rising stars of the Tory party, who have advocated a tough set of work reforms in a new book.

According to leaked extracts from the book, Britannia Unchained – Global Growth and Prosperity, five Tory MPs from the "class of 2010" call for a culture of "graft, risk and effort" to propel Britain into the "superleague" of nations.

The book contains a blueprint of radical reforms. The MPs – Kwasi Kwarteng, Priti Patel, Dominic Raab, Chris Skidmore and Elizabeth Truss – say: "Once they enter the workplace, the British are among the worst idlers in the world. We work among the lowest hours, we retire early and our productivity is poor."

The MPs claim the UK workforce should model itself on the workers of South Korea, Singapore and Hong Kong, rather those in European nations – or watch living standards fall away.

The Evening Standard reports the authors as saying: "Britain will never be as big as China or Brazil, but we can look forward to a new generation, ready to get to work. If we are to take advantage of these opportunities, we must get on the side of the responsible, the hard working and the brave. We must stop bailing out the reckless, avoiding all risk, and rewarding laziness."

The 184-page book will be published shortly before the Conservatives' autumn conference. In it, the five rehearse well-worn Tory themes about how the welfare state has sapped the strength and vigour of the British economy. "We work among the lowest hours, we retire early and our productivity is poor," they say in the book.

Kwarteng told the Standard: "We need to look beyond Europe for economic success. We should be starting now. There is no reason why we can't be pushing ahead with a lot of this. [London mayor] Boris [Johnson] when he talks about big infrastructure projects, deregulation and cutting taxes, is absolutely on the money."

He added: "There is definitely a new right, which is much more international in its focus. The old Tory right are a busted flush."

The Guardian contacted all five MPs on Friday. Only Raab responded but declined to comment, saying the Standard had "broken the book's embargo".

Labour attacked the claims by the Tory backbenchers – and called on David Cameron to distance himself from their views. Chuka Umunna, shadow business secretary, said: "First they blame British businesses for their economic failures and now they blame the people who work within them, showing how out of touch the Tory party has become.

"Arguing that working Britons are 'the worst idlers in the world' is deeply insulting. People who work hard, play by the rules and pay their taxes shouldn't have to put up with Tory MPs calling them lazy – especially when prices are rising faster than their wages, their tax credits are being cut and Britain is in a double-dip recession made in Downing Street."

The controversial comments come days after Johnson urged the prime minister to stop "pussyfooting around" over plans to build another London airport and reduce the strain on Heathrow.