Brian Binley made the attack on his blog yesterday, accusing the Prime Minister of not standing up to Liberal Democrat demands, and demanding that he change direction
With a Cabinet reshuffle expected within weeks, Mr Binley wrote:
"What the country, the Conservative party and the captain of the ship needs now is not so much a reshuffle as a rethink. "The polls tell a consistent story and point to one inevitable conclusion. "Rearranging the deckchairs on the Titanic will do nothing to alter the impression that the ship has lost its way. "It's a change in direction which is needed and wanted."
Mr Binley, treasurer of the 1922 Committee of backbench Tories, said the Prime Minister needed to listen to his backbenchers and pay more attention to traditional Tory values.
The Prime Minister is unlikely to be feeling that well disposed towards outspoken backbenchers though, given that Mr Binley is the third MP from the East to attack him publicly this week.
Mr Binley's intervention follows the criticism of Suffolk MP Tim Yeo, who questioned the Prime Minister's political courage over the issue of a third runway at Heathrow, asking if the Tory leader was "man or mouse".
Nadine Dorries, the MP for Mid Bedfordshire told Anglia News that concerns about Mr Cameron's leadership are widespread in the Conservative party and he needs to come up with better economic policies.