Union bosses are demanding “plans not spin” from Scottish ministers over its strategy to ramp up the installation of heat pumps.

The appeal comes after new figures from the Microgeneration Certification Scheme (MCS) database revealed that 6,338 heat pumps were installed in Scotland in 2023, a 37% increase over the space of two years.

Patrick Harvie, Green Zero Carbon Buildings Minister, has welcomed the progress but admitted “there is more to do” as part of the heat transition.

But GMB Scotland has warned the number of installations was less than a tenth of the Scottish Government’s annual target and claimed the figures have only exposed the widespread and continuing reluctance of Scots to invest in the new technology.

Read more: Scotland's leads UK for heat pump installations but 'more work to do'

The union has repeatedly criticised the Scottish Government’s renewable heating strategy and its focus on heat pumps.

Claire Greer, GMB Scotland’s organiser in energy, said it is time for SNP and Green ministers to face reality and urgently forge new paths towards green energy.

She said: “We need far fewer Scottish Government press releases about heat pumps and far more realism and effective planning.

“We do not need more spin, we need more plans.”

Ms Greer added: “Simply telling Scots again and again that they should fit this expensive technology is not working during a cost of living crisis and will not work in the future either.

Read more: Analysis: Let's not blow cold over heat pumps win

“There are practical, impactful things that can be done right now to cut Scotland’s emissions and support the transition to renewables, from insulating homes to retooling the existing gas network.

“There are many ways to a greener future too, including the adoption of new nuclear, but blithely insisting Scots want heat pumps when every bit of evidence suggests the opposite is no longer credible and only diverts attention from far more practical, impactful measures.”

Mr Harvie launched a consultation on his legislation that would set dates for renewable heating systems to be installed.

Under the proposals, most of Mr Harvie’s timescales set out in his initial strategy in 2021, remain intact.

Mr Harvie announced that off-gas homes, which were initially set to make changes from 2025, will now align with the majority of properties that are on gas mains supply.

Under the plans, all homes will need to end their use of fossil fuel emission heating systems by 2045, when Scotland is due to become net zero in law.

Read more: 100k could avoid heat pump installation as heat networks to ramp up

But modernised energy efficiency standards, which could take the type of heating system into account, as well as the insulation and fabric of the building, will need to be met from 2028.

The draft plans set out that privately rented homes will be required to meet a minimum energy efficiency standard no later than 2028, while owner- occupied homes will need to meet those same standards by the end of 2033.

Mr Harvie said that all homes and non-domestic buildings will be required to end their use of polluting heating by the end of 2045.

But in order to create a smooth trajectory towards 2045, the minister said that those purchasing a home or non-domestic property before 2045 would be required to end their use of polluting heating systems within a specific grace period following that purchase.

Under already-agreed planning rules, all newly built homes will be banned from installing a fossil fuel heating system from April 2024.