Amid a fierce backlash from government conservatives and speculation his job was under threat, Coalition frontbencher Christopher Pyne has been forced to apologise for a controversial speech he gave to Liberal moderates.

Mr Pyne, who was under pressure for telling a meeting of Liberal moderates that same-sex marriage would become law “sooner than everyone thinks”, said he was “very sorry” his comments had “caused such a distraction for the government”.

“My remarks were ill-chosen and unwise and I can see how unhelpful and damaging they have been,” he said on Wednesday night.

“The truth is, Malcolm Turnbull runs a tight-knit, traditional Cabinet government that is inclusive of all strands of thought across the party.”

The Leader of the House had also infuriated conservatives by talking up the dominance of the moderate faction under the Turnbull-led Liberal Party. His comments were recorded and leaked to the media.

The apology came after Tony Abbott suggested he understood why his colleagues might want the senior frontbencher replaced from his position as the government’s chief parliamentary tactician.

Prime Minister Malcolm Turnbull had joined government ministers in publicly rebuffing calls for Mr Pyne to be sacked or demoted from his role on Wednesday.

Asked directly if he backed Mr Pyne, Mr Turnbull replied: “I have an outstanding ministry and all of my ministers have my support.”

Senior government figures including Treasurer Scott Morrison and Social Services Minister Christian Porter also dismissed calls for Mr Pyne to be sacked.

Speaking at an event in Cooma to spruik the Snowy Hydro 2.0 project on Wednesday, Mr Turnbull made a pitch to government conservatives.

“There is nothing more conservative than ensuring you have affordable and reliable electricity,” he said.

Mr Porter, considered one of the Coalition’s conservative rising stars, said Mr Pyne was doing a “marvellous job” and hit back at claims the government had shifted to the left.

“If you look at my area … you would hardly describe what we’ve been doing in terms of root-and-branch welfare reform as a shift to the left,” he told Sky News.

The Prime Minister also responded to Mr Abbott’s attacks on the Renewable Energy Target, which came as the former leader outlined an alternative policy manifesto he said was aimed at winning the next election.

“Let me just remind you that the Renewable Energy Target was recently renegotiated and legislated in 2015 while Mr Abbott was Prime Minister,” Mr Turnbull said.

“So the law has been passed, the law has been confirmed, there is certainty in the industry, investments are being made and what is needed to make renewables reliable is obviously storage.”

The PM added: “I’m not into political slogans. I’m into engineering and economics.”

His comments followed Mr Abbott releasing a six-point policy plan on Tuesday.

Later in the day, Mr Abbott repeated his criticisms of Mr Pyne, saying his speech to moderate Liberal Party members was “poor” and came at the “worst possible time for the government”.

Despite saying Mr Pyne’s position was a matter for the PM, Mr Abbott added: “It was a very, very ill-advised speech and I can understand why some of my colleagues might be saying his position as leader of the House is now difficult to maintain.

“When a senior member of the government says something like this, obviously it has some ramifications.”

Mr Abbott also did not deny that he had told conservative colleagues he planned to remain in politics to offer experience when “things go badly under Malcolm”, as reported by News Corp.

Describing his position in Parliament as a “vocation”, he said he regarded himself “as in this business for the long haul”.

“What I say publicly and privately is I still have a role to play in public life,” he told 2GB.