Cabinet minister Malcolm Turnbull has made an extraordinary attack on conservative News Corp writer Andrew Bolt, describing his column today as bordering “on the demented”.

Turnbull told reporters that for Bolt to “string together” a dinner he had with Clive Palmer last week and his attending the launch of a cross party group of friends of the ABC and say that amounted to some kind of threat or challenge to Tony Abbott was “quite unhinged”.

“Now, Mr Bolt is fond of attacking what he regards as the government’s enemies in the media. Principal amongst whom of course he numbers the ABC. I don’t think you would see anything as crazy as that on the ABC.

"I just have to say to Mr Bolt, he proclaims loudly that he is a friend of the government. Well with friends like Bolt, we don’t need any enemies,” Turnbull said.

Turnbull had been asked about speculation that there could be some kind of leadership issue in the Coalition.

In his News Corp column today, Bolt wrote that Turnbull’s dinner with Palmer at a Canberra restaurant sent “an unmistakable message to Liberal MPs - replace Abbott with Turnbull as prime minister and maybe Palmer will play ball [with the government]”.

Bolt went on: “In fact, Turnbull has lavished a lot of charm lately on Abbott’s natural predators, even last week launching a new parliamentary group of friends of the ABC, which got a (small) cut in the budget.”

Bolt said this was Turnbull “on the far left of the Liberal party, charming a constituency that hates Abbott and which would back Turnbull to replace him - even if it still wouldn’t vote Liberal.

"If only Turnbull had spent half this charm fighting for Abbott’s budget,” Bolt wrote.

Turnbull has said that he, Liberal federal vice-president Tom Harley and a business associate of Harley’s were going to dinner when they ran into Treasury secretary Martin Parkinson, who joined them; Turnbull texted Palmer to ask him along too.

Turnbull’s attack is likely to meet with a divided response within the Liberal party. Many conservatives within the party are fans of Bolt, but some other Liberals are critical of him, regarding his views as extreme.

On Sunday Bolt, interviewing Abbott on the Ten network, asked Abbott why Turnbull was wooing Clive Palmer on his own. “It looks like he’s got his eye on your job,” Bolt said.

Abbott replied that it was “perfectly reasonable” for senior members of the Coalition to talk with crossbenchers, because the government had a budget to get through parliament and also needed the repeal of the carbon tax and the mining tax to be passed.

In response to the Turnbull attack, Bolt told Fairfax Media today: “It’s a great shame and quite telling that Malcolm Turnbull attacks someone he calls the government’s media friend with far more vitriol than I can recall him ever attacking one of the government’s media enemies.

"This fits a pattern. No doubt he [Turnbull] will expand on this in his next Q&A appearance with Tony Jones.”