Green campaigners have dismissed claims that building more gas plants would help the UK cut emissions as “ridiculous”, insisting a new “dash for gas” would leave the country locked in to a high carbon trajectory.

Think-tank Policy Exchange drew the ire of renewable energy proponents by arguing in a new report that bringing forward new gas generation instead of more expensive developments such as offshore wind would free up resources to help further other green technologies.

It says bringing forward gas generation instead of 4GW of capacity of the planned 32GW deployment of Round 3 offshore wind and then retiring those gas plants early would save the country around £700-900m a year and still allow for 9GW of offshore wind to be built.

The report suggests around £280m of this money could then be spent on doubling research into low carbon technologies, £125m invested in improving household energy efficiency, and the remainder used to purchase and retire a level of carbon credits Policy Exchange claims would offset the gas generation’s emissions six times over.

It proposes scaling back deployment plans for “the most expensive generation technologies” and associated subsidies, such as the Renewables Obligation and the Contracts for Difference feed-in tariff outlined in last month’s draft Energy Bill.

Policy Exchange also rejects the idea that once new gas plants are built there will be pressure to continue with the fuel at the expense of renewable energy deployment and the target of decarbonising the UK’s power sector by 2030, which the Committee on Climate Change says must be met to keep within the country’s mandatory carbon budgets.

The report says a strong emissions cap set by the EU would ensure only the most economic gas would continue to operate, while the remainder would shut down, become back-up stations or be fitted with carbon capture and storage technology. Extending this cap to 2035 would provide greater certainty for investors and allow the market to decide which technologies can deliver the cheapest emissions reductions, Policy Exchange says.

“Subsidised deployment helps us to discover which technologies are likely to become competitive. But we must not put too much money on a few, unproven horses,” said report author Simon Less. “We need to make best use of limited resources to maximise emissions reduction and overall low carbon innovation.”

However, the conclusions were roundly rejected by Jenny Banks, policy officer at WWF-UK, who cited the alarming effects of a global “dash for gas” outlined in last week’s International Energy Agency (IEA) report.

That warned a rise in gas-fueled plants could result in temperature rises of 3.5 degrees of warming, well above the two degree limit most scientists say will avoid the worst effects of climate change, and said emissions gains from replacing coal with gas tend to be counteracted by higher demand and lower investment in low carbon fuels.

“It’s ridiculous to expect that a dash for gas at the expense of building renewable generation would somehow lead to bigger carbon cuts,” Banks said in a statement. “This is based on a very idealistic view of the effectiveness of the EU emissions cap which, while important, is vulnerable to political lobbying and does not provide the certainty required to bring forward investment in low carbon generation.”

She added Policy Exchange had ignored the economic benefits to the UK in developing world leading renewable energy industries.

“To make the most of our unique North Sea renewables resource and to reap the benefits of job creation, the sector needs targeted, time-limited support and long-term certainty,” she said, “which are far more effective in driving innovation and deployment at scale.”