Business leaders have warned that Tory plans to cap energy prices could hit investor confidence.

The CBI was responding to the Tory's election pledge for industry watchdog Ofgem to set a cap for the default standard variable tariffs.

Writing in the Sun newspaper the Prime Minister Theresa May said gas and electricity bills were eating up more and more of the monthly pay packet.

It was reported that the cap could save about 17 million customers up to £100 a year.

Josh Hardie, Deputy Director-General of the CBI which represents 190,000 businesses, said: "Putting customers at the heart of the energy market is important for everyone.

"The Competition and Markets Authority's thorough two year investigation identified low levels of consumers switching energy providers as a challenge, and put forward a range of recommendations to address this.

"It is important that these measures bed in before looking to further interventions.

"A major market intervention, such as a price cap, could lead to unintended consequences, for example dampening consumers' desire to find the best deal on the market and hitting investor confidence."