Coal-fired power plants could be allowed to run beyond 2025 if they make at least partial use of carbon capture and storage (CCS), the Independent has reported.

In her energy reset speech in November energy secretary Amber Rudd promised to phase out all unabated coal generation by 2025. A consultation on the planned cut-off was originally meant to be launched this spring but still hasn’t materialised.

An unnamed Whitehall source was quoted by the paper as saying: “If coal is partially abated, if you have installed CCS, could you carry on burning coal? These are all the points the consultation is going to try to address and set out what would be allowed and seek people’s views on it.”

He continued: “The consultation will very clearly set out if you have got a coal power station basically what happens after 2025… If you are fitting it with CCS, it will set a level of sorts at which this will not be allowed.”

The source said the government could still decide to halt any coal generation that does not have zero carbon emissions, adding that the discussions taking place were still “pure speculation” at this point.

According to the minutes of a meeting of the coal forum in February, energy minister Andrea Leadsom “encouraged industry to engage in the consultation” by, for example, questioning “what is ‘unabated coal’?”

A spokeswoman for the Department of Energy and Climate Change (Decc) said: “Unabated coal is the dirtiest, most polluting way of generating electricity.  The government is absolutely committed to phasing out power production from unabated coal by 2025 and it is nonsense to suggest otherwise.  We made this clear last year and nothing has changed.”

She said the consultation on the coal closures will be published in the coming months and will seek to clarify what exactly is meant by unabated coal.

According to recent figures from Decc coal generation collapsed in the first three months of 2016, supplying 50 per cent less power than in the same period last year.