Conservative MP Nadine Dorries has warned Tory leader David Cameron he will be kicked out of office by his own backbenchers within the next year unless he "dramatically" changes the party's policies.
In an outspoken attack, the politician described the Prime Minister and his Chancellor George Osborne as "dangerous", saying they were leading the Conservatives "towards defeat" at the next general election.
The MP for mid-Bedfordshire also hit out at Mr Cameron's "sneering" attitude and claimed backbench discussions about introducing a motion of no-confidence against the leader were already taking place following a dismal display at Thursday's local elections.
Ms Dorries told BBC 5Live's Stephen Nolan Programme: "What we have seen on Thursday was pretty bad. A year from now we have bigger local elections and unless we change dramatically what we are doing now we could see even bigger losses.
"The (Conservative) MPs in the House of Commons will not sleepwalk towards a next general election like Labour MPs did and watch their seats disappear because of bad policy."
Ms Dorries warned that if the party did not change what it was doing "dramatically and look at what people are asking for and provide them with that", Tory backbenchers would start filing their letters of no confidence in Mr Cameron and look for a change of leader.
"I happen to know this is already being discussed," she said.
During the the deeply personal outburst Ms Dorries also accused Mr Cameron and Mr Osborne of arrogance, saying they were "leading the Conservative party towards defeat".
She said: "I don't have anything against anyone who is posh, what I do have though is a problem when arrogance is mixed with privilege and you throw bad manners into the mix, I think that is a pretty dangerous combination."
The MP criticised Mr Cameron's "demeanour" and accused him of failing to listen to party members and the voices of constituents.
She also accused him of a "sneering disregard for anyone who dares to stand up and oppose him and say 'do you think you are getting this quite right"'.
Ms Dorries said she was not worried if her rebellious comments meant she was stripped of the whip, but argued it would "reflect badly" on the Conservative Party if she did.
She added: "My loyalty is to true Conservative Party values and we do not have true conservative values in our party at the moment - we have a predominance of Liberal Democrat values.
"I feel slightly hacked off when I get to the point that I am and I try to represent other people who want to better their lives and they are not being listened to. I am there to represent their voices and their voices aren't being heard."
Writing today for the Mail on Sunday, Ms Dorries warned that only 46 signatures were needed from Conservative MPs in order to challenge Mr Cameron as leader, and added: "I would guess that those signatures are already coming in and will reach 46 by Christmas."
Speaking to the BBC's Andrew Marr, Chancellor George Osborne dismissed Ms Dorries' comments.
He said: "Nadine Dorries for the last seven years hasn't agreed with anything that either myself, David Cameron or indeed most Conservatives ... have done.
"She has objected to the modernising of the Conservative Party. We have got to focus on what really matters. I think the issues that matter are actually not House of Lords reform, not gay marriage, which are the issues she raises.
"They are the economy, the education system, the welfare system, our police and the NHS. These are the issues that the public want us to deliver."