Boris Johnson has hinted he is cautious over plans for an onshore wind revolution amid Cabinet fears that it would mean thousands of turbines are built in Tory heartlands. 

At a hearing of Parliament’s Liaison Committee, the Prime Minister stressed his support for offshore wind in a sign that he is less convinced about the need for a major increase in projects on land.

It comes amid Cabinet disagreements over a proposal to rip up 2015 planning reforms that made it almost impossible for new onshore turbines to be built. The change, which is being debated as part of a wider overhaul of energy policy, would pave the way for new wind farms across swathes of rural England.

Mr Johnson told MPs that he was keen to take action that will help wean the West off Russian gas.

He said “you have got to recognise that in the UK we have just failed, for a generation, to put in enough long-term supply”, and added: “It’s been one of those colossal mistakes. Renewables are fantastic: offshore wind – and I stress offshore wind – I think has massive potential. But so does nuclear.”

A Downing Street source cautioned against reading too much into the comment, stressing that no final decision had been made about a new onshore wind drive.

For much of the last decade the value of building wind turbines on the UK mainland has been a fiercely debated issue within the Conservative Party.