Fergus Ewing has called for the SNP to withdrawn from the Bute House Agreement with the Scottish Greens after the phase out of boilers and their replacement with heat pump is set to be delayed.

The former cabinet secretary for rural affairs spoke out after the Herald on Sunday revealed that the timetable to begin removing fossil fuel run heating appliances from 2025 is to be moved back.

Sources told the paper the date is not likely to be included in a consultation on proposals for a Heat in Buildings Bill due to be published by the end of the month.

READ MORE: Ministers to delay plan for heat pumps to replace boilers from 2025

It is not clear whether a target set in 2021 by zero carbon building minister Patrick Harvie to have more than 1 million heat pumps or other green energy heating systems installed in Scottish homes by 2030 will be in the consultation.

A ban on the installation of gas boilers in new build homes will go ahead from next April. Instead all new properties will have to be fitted with heat pumps or other form of green energy heating systems.

The delay to the 2025 date is the latest Scottish Government environment policy to be hit by set backs in recent months following the shelving of the deposit return scheme (DRS) and the highly protected marine areas (HPMAs).

The Herald: Patrick Harvie, left, and Lorna Slater, right, co-leaders of the Scottish Greens pictured with former First Minister and SNP leader Nicola Sturgeon, as they unveil the Bute House Agreement. Photo PA.

Mr Ewing has been a prominent critic of his party's co-operation with the Scottish Greens, whose co-leaders Mr Harvie and Lorna Slater are both ministers in the Scottish Government.

Mr Ewing, the MSP for Inverness and Nairn and former minister for business and energy, told The Herald: “These heat pump targets were always green pie in the sky.

"Currently in Scotland, there are just a few thousand heat pumps installed each year with only around 200 firms able to do the work - mostly one or two man bands."

The Highland MSP described Mr Harvie's target to have more than one million heat pumps or other green energy systems in homes as "total fantasy."

He said: "To meet the 2030 Harvie target we would need to increase this  to over 100,000 a year.  Plainly unachievable and impossible. This  is not competent Government. It’s  total fantasy.  

"So Patrick’s heat pump plans join the Green Party led Deposit Return ( DRS)  and  Highly Protected Marine Areas ( HPMA)  in the ever- burgeoning Scottish Government Policy recycling unit.      

"The most serious thing is this - each one of these daft schemes cost business a great deal of time and money.  Millions of pounds - tens of thousands of wasted hours.

"We should be helping them instead,  by cutting swingeing business rates bills on for example, hotels and  pubs, not hitting businesses, struggling to recover from Covid , with madcap wheezes

"To regain any semblance of credibility in business circles and avoid yet more Green banana skins  Humza must ditch the dire  dalliance with the gaffe prone-extreme  Greens before it costs the SNP even more loss of trust and  support.  

"It’s  time for  “Taxi for Harvie” - or better still, and with transportation  more to their liking perhaps :  “Tandem for Harvie and Slater.”   

A Scottish Government spokesperson said: “The Bute House Agreement represents a new model of co-operation and has resulted in considerable progress on issues that matter to the people of Scotland, including increasing the Scottish Child Payment to £25, introducing free bus travel for young people, working towards a new National Park, bringing ScotRail into public ownership and launching a £65m Nature Restoration Fund.

“Only last month a wide range of businesses and stakeholders wrote to the Scottish Government highlighting the importance of regulation of the move to clean heating to support business investment. We have already led the way in our New Build Heat Standard which ensures that all new buildings warranted from next April will have clean heating. Our further plans will be published shortly.”