The energy minister Angus Taylor has confirmed the Morrison government is continuing to assess new coal generation projects despite pushback from moderate Liberals, but he says taxpayers will only support projects that are “viable”.

In a statement to Guardian Australia, Taylor confirmed the government was continuing to consider 10 coal projects through its power generation underwriting program, as well as new gas and pumped hydro proposals.

Taylor said the government would not seek to pick any particular firmed generation over another, consistent with the advice of the Australian Competition and Consumer Commission. The ACCC recommended limited government underwriting as a means of increasing competition in the generation sector.

“The prime minister has made it clear the government will only support projects that are viable,” Taylor said. “The government is carefully considering all proposals. These are big projects and we’ve got to get this right.

“The government has been upfront about our intentions to ensure there is new generation to tackle the demand challenges facing the electricity grid – this is what our underwriting new generation investment program seeks to do, and we have received strong response to it.

“We want projects that reduce prices and improve reliability and are consistent with our international obligations.”

Taylor’s confirmation that new coal generation projects remain on the table for consideration comes as an open brawl is continuing within the Coalition about energy policy.

Queensland Nationals and the former deputy prime minister Barnaby Joyce are demanding the government commit taxpayer support to new coal regardless of whether or not the projects stack up economically, and city-based Liberals, under pressure from their constituencies, are pushing back against that offensive.

As well as tensions between Liberals and Nationals, there are also tensions between Nationals in different parts of the country, with Victorians demanding Joyce and others maintain discipline.

The Nationals deputy leader Bridget McKenzie said of Joyce’s public interventions in recent days, that “Australia is frustrated, you know, that there is a politician out there that is not focused on their needs and issues”.

The New South Wales Nationals leader John Barilaro – on the hustings in the NSW state election – was even more forthright, urging his federal counterparts to “shut up” and stop navel-gazing.

With polls showing Australian voters are concerned there is not enough action on climate change, Liberals have pushed back against the coal sortie from Queensland.

The Brisbane Liberal Trevor Evans said the economics of coal did not stack up “and quite frankly the party room would not support it”.

Victorian Liberal Tim Wilson said if the economics of a coal project stacked up, the private sector would build it. “I’m not a fan of the government getting involved and building new coal-fired power stations. I don’t believe that is Coalition policy or ever has been,” Wilson told the ABC.

Sydney Liberal Trent Zimmerman said “a Liberal government should not be in the business of building new coal-fired power stations in circumstances when the market is not prepared to do so”.

Zimmerman later told Sky News there could be a case for the government to be “underwriter of last resort” to boost competition “as long as there was a business case … and [coal] is competitive with other projects in emissions intensity”.

But he added there were questions about whether a new coal plant was a sensible development given Australia was required to meet its Paris targets.

With Nationals agitating for a concrete outcome both publicly and privately, Zimmerman also noted there was “no rush” to sign off on projects before the election.

With the coal debate fracturing the government, and with some Nationals suggesting a lack of action on coal could imperil the Coalition agreement, Scott Morrison was at pains on Tuesday to emphasise harmony between Liberals and Nationals.

During a speech in Melbourne, Morrison compared his relationship with the Nationals leader Michael McCormack to that of Robert Menzies and then Nationals leader John “Black Jack” McEwen.

“In the same way that Ming and Black Jack work so well together, over all of those years, I can tell you that ScoMo and Big Mac over here are doing exactly the same thing,” Morrison said.

“It’s a strong bond.”