“You can’t cap energy bills while denying the lowest cost option a chance to compete. Having seen the record-breaking fall in the cost of offshore wind, we now need to discover how much the cost of onshore wind has fallen too – and that hasn’t been possible for over two and a half years because it’s been excluded from competitive auctions,” she said.

Peter Aldous, vice-chair of a renewable energy all-parliamentary group, blamed the previous Labour Government for allowing wind farms to be imposed on communities, with “politically toxic” results.

“A lot of Tory MPs don’t want onshore wind in their backyards. Under the last Labour government, they were being imposed and communities didn’t like it but if communities want them they should be allowed them,” he said on the fringes of the conference.

The warmer words for onshore wind comes ahead of fresh findings from Energy UK, to be published later this week, which underlines the growing concern among investors over Britain’s plans for subsidising energy beyond 2020.

A sector-wide survey by the trade body has found that the £180bn still needed to overhaul the generation market by 2030 could be at risk unless the Government gives clarity on its long-term plans.