It is difficult to see how Caroline Lucas can claim that the Green councillors on Kirklees Council in Yorkshire were responsible for the warm zone project (Letters, December 16).

There are only four Greens out of a total of 69 councillors on Kirklees Council and there has been no administration since 2006.

The support for this project was across all parties including Labour, Liberal Democrat, Tory and Independent, the Greens playing a minor role.

Funding for the project came from a mixture of public and private money, including some from Scottish Power and other utilities.

It would also be interesting to see a breakdown of how a saving of £150 per family would be achieved – this represents about 12 per cent of my average yearly bill.

Insulation can only save money on the portion of a bill used for heating – not lighting, running electrical equipment or water heating.

This figure seems very high. Were none of the 40,000 homes insulated at all? As an MEP and Green party parliamentary candidate Caroline Lucas must know her claims are at best doubtful.

Alan Robins Burlington Gardens Portslade