Boris Johnson, Mayor of London, has urged the chancellor to “send the right signals to the market” by keeping the FiT rate at its current level.

In a letter seen by the Financial Times, the Mayor of London details his recommendations for the growth review on November 29.

Mr Johnson writes: “While Government will argue that the costs of solar panels have reduced, the costs of inverters, stands and labour have not”.

In his letter, Boris Johnson acknowledges the financial constraints that currently exist and the importance of cutting the deficit. However, he warns that the proposed cut to the solar subsidy will undermine the development of Britain’s renewable energy industry.

“A reduction of 50 percent in the feed-in tariff effectively slowly suffocates the growth that the policy has so far encouraged,” he concludes.

The Mayor of London’s criticism over the proposed FiT cut is the latest in a number of high profile groups calling on Government to reconsider the outlined proposals, with ministers set to defend the cuts during an opposition day debate in the commons on Wednesday.