Boris Johnson has said he is “very concerned” about the impact a proposed 87% cut to the feed-in tariff will have on the solar industry, constituting something of a rebellion from the Conservative Mayor of London.

Johnson was quizzed for his take on the proposals at this afternoon’s Mayor’s Question Time by Green Party assembly member Jenny Jones who asked whether or not the mayor was examining the potential impact the cuts would have on solar deployment in London, which is already lower than anticipated.

He responded by stating his concern for the industry, referenced the potential loss of up to 10,000 jobs and said his department was “doing what we can do” to understand the potential impacts more by talking to solar’s administrative bodies.

In stating his concern Johnson has gone against his own party's message which has been that the cuts follow much larger than expected roll-out of solar which has overstretched subsidy allowances under the Levy Control Framework. The Department for Energy and Climate Change's impact assessment also glossed over the potential loss of jobs within the industry, stating it would be impossible to quantify the impact without consulting the industry first.

Johnson said his understanding of the reasoning behind the cuts was down to the substantial reduction in solar panel costs, but added that it was “wrong to cut if will stop people investing” in the technology.

Concern over diminishing confidence in the UK’s renewable investment market has continued to mount today after both the Committee on Climate Change and Big Four consultancy EY said the government had continued to place confidence at risk.

Jones pushed Johnson further by stating that the government had been conducting a “bonfire of renewables” since being elected in May and asked him whether or not his concern would result in him going against his party and commissioning a report.

The mayor responded by asserting that his team was “all over this” and that Matthew Pencharz, deputy mayor for environment and energy, was examining the proposals to establish whether or not they would be “as damning as suggested”. Johnson then suggested he would “throw his toys out of the pram” if the proposals placed London’s renewables commitments at risk.

“We need to understand the implications… London has made progress and we can’t see it go backwards… I will stick up for London and its environment,” Johnson added.

Johnson was speaking after a lengthy delay to proceedings following a protest from London taxi drivers within the council chambers. Responding to driver concerns over the uptake of electric vehicles in central London the mayor referred to them as “luddites”, causing a fracas which resulted in several chamber staff being hurt and the police to be called.