David Cameron has dismissed an accusation from one of his own backbenchers that he is out of touch with voters because of his privileged upbringing.

Mid-Bedfordshire MP Nadine Dorries, a frequent critic of the government, told the Financial Times that the prime minister and chancellor George Osborne's plans to cut child benefit for middle income families was misplaced.

"The problem is that policy is being run by two public school boys who don’t know what it’s like to go to the supermarket and have to put things back on the shelves because they can’t afford it for their children’s lunchboxes," she said.

She added: "What’s worse, they don’t care either.”

Cameron said the accusation was "nonsense" when asked about it by Labour MP Sharon Hodgson during prime minister's questions on Wednesday.

From January next year couples with at least one parent earning more than £42,745 a year will lose child benefit. However opponents have argued it is unfair as family where two parents earn just below that amount will be able to keep it, even if their combined income reaches as high as £80,000.

Speaking in the Commons today, the prime minister said the measure was necessary in order to tackle the budget deficit. He said it was unfair that people earning around £25,000 had to pay to look after the children of the rich.

"Of course it is a difficult decision, life is about difficult decisions, government is about difficult decisions," he said.