Liberal Senator Cory Bernardi has criticised Cabinet minister Malcolm Turnbull’s response to conservative columnist Andrew Bolt as “unwise”, “inappropriate” and “too strident”.

Senator Bernardi, from the Liberal Party’s right wing and Mr Turnbull from the party’s moderate or left wing, have been political enemies since the bitter carbon trading debate in 2009, which cost Mr Turnbull the Liberal Party leadership.

Mr Turnbull has bristled at suggestions he is once more angling for his job by embracing Tony Abbott’s “natural enemies”, a claim repeatedly made by Bolt.

The Communications Minister has described Bolt’s latest column as “unhinged”, “deranged” and “bordering on demented” for claiming that his mid-week dinner with Clive Palmer and treasury boss Martin Parkinson was aimed at sending a leadership signal to colleagues.

Mr Palmer is refusing to negotiate with Mr Abbott until he is given more taxpayer funded staff.

A former staffer to Mr Turnbull has told the ABC Mr Turnbull and Mr Palmer have long been friends and their friendship predates Mr Turnbull’s leadership of the party.

But Bolt told the ABC’s 7.30 his theory has been proved correct because Mr Turnbull’s “nasty”, “over the top” and “amazingly abusive attack” shows he wants to stoke the leadership story so it will continue to run in the media.

“Malcolm Turnbull could have chosen not to say anything about my article, the fact that he did shows he wants this story to run and that just destabilises Tony Abbott,” Bolt told Sabra Lane in the interview.

Liberal Senator Cory Bernardi agrees, telling Q&A Mr Turnbull’s attack was “too heavy”.

“Everyone in entitled to their opinions,” Senator Benardi said when asked by host Tony Jones what he thought of the developments.

“I thought that Malcolm’s response was too strident, I though it was inappropriate, it was unwise to do and I think it’s just kicked the whole thing along.

“Andrew is entitled to his opinions, I think he is a very principled man.

“Malcolm I just think went a bit too heavy today.”

Lucy Turnbull says dinner has been ‘completely miscast’

Mr Turnbull’s wife Lucy, who appeared on Q&A alongside Senator Bernardi downplayed her husband’s dinner with Mr Palmer that has sparked media speculation.

She said Malcolm told her he was coming down “with the most desperate dose of the flu” and was heading out for some “spicy soup” before an early night.

Mrs Turnbull said she assumed her husband was in bed by 7pm, but he texted her in early the next morning to say “Clive came along” to dinner.

It was completely random [and] spontaneous,” she said. “It was completely miscast.”

Mr Turnbull said he and his friend, Liberal Party vice-president Tom Harley planned to go for dinner and bumped into Martin Parkinson in the Parliament House carpark.

Later, after they had already begun dining, Mr Turnbull sent Mr Palmer a message to invite him to join the gathering.

Bolt seized on the dinner date to ask Mr Abbott whether Mr Turnbull was angling for his job, during their television interview on the weekend.

The ABC understands Mr Turnbull was perturbed by the question and was reassured by Mr Abbott on Sunday night that it was in no way set up by the Prime Minister or his office.

Mr Abbott was dragged into the spat in Question Time, when Labor sought to embarrass him by asking whether he backed his “friend” Andrew Bolt or “frenemy” Malcolm Turnbull.

The Prime Minister said he was proud to have been campaigning with Mr Turnbull on the weekend and backed his colleague in the dispute.

“In any dispute between a member of my frontbench and a member of the fourth estate I am firmly on the side of my frontbencher,” Mr Abbott told Parliament.

Bolt told 7.30 he did not expect the Prime Minister to back him over the Cabinet minister, but added “yet”.