A Conservative MP ordered to end critical comments on the party leadership on Twitter has said she will not be silenced.
Sarah Wollaston was among Tory MPs to face the wrath of David Cameron's strategy chief Lynton Crosby at a meeting of backbenchers on Tuesday.
The Australian spin doctor told the MPs they had to decide whether they were "commentators or participants".
Mrs Wollaston said she felt "uncomfortable" about his remarks.
"I think it's important that if you are a backbench MP you're there to be a critical friend and to scrutinise government policy," she told the BBC News website.
"To send out a message that says as a backbench MP you are a 'participant not a commentator,' I'm very uncomfortable with that message. I don't think that's the right message to send out."
The Totnes MP, who was selected in an open primary, said she considered herself a "Cameron loyalist" who believed talk of leadership challenges should end.
But she said she did not get into politics to be "lobby fodder" and reserved the right to comment on policy, or the party leadership, when she felt it was warranted.
"I think that my job as a backbench MP is to be able to commentate, on behalf of my constituents, on important issues of the day and sometimes, of course, that will be uncomfortable for the executive."
One recent Tweet quoted in the press, saw Mrs Wollaston writing: "Inner circle still look far too posh, male and white and Cameron is running out of time to fix it".
She said she was "making a valid point about how the public view us and whether or not we need to make the cabinet sound more like modern Britain".
She said it was "ironic" that Mr Crosby's plea for party unity was leaked to the media before Tuesday evening's meeting.
Other Tory MPs to have criticised the party leadership on Twitter include Michael Fabricant, who accused it of sending "mixed messages" over immigration and Peter Bone, who said it was "wrong" to commit 0.7% of state spending to foreign aid.
Mr Crosby, who masterminded London Mayor Boris Johnson's re-election and Michael Howard's election campaign in 2005 - urged Tory MPs at Tuesday evening's meeting to focus on selling the party's message and stop airing divisions on social media.
They were also told to stress that the next election would be a choice between having Mr Cameron or Ed Miliband in Downing Street.
Labour Vice Chairman Michael Dugher said: "Things are so bad for Cameron that he is reduced to gagging his own backbench MPs on Twitter because he is fearful they will tell it how it is.
"This is a weak and increasingly out of touch prime minister desperately trying to stop his divided party imploding."