to again assess competition in the energy market, on 26 June 2014, Ofgem referred the energy market in Great Britain to the CMA for an investigation. An interim report by the CMA, published in 2015, claimed that energy suppliers were overcharging customers by as much as £1.7 billion. The CMA's findings and proposed remedies, published in 2016, included a price cap for energy customers who were on prepayment meters – but were widely criticised for not going far enough. By March 2017, Citizens Advice, which had taken on the funding and responsibilities of Consumer Futures to advocate for energy consumers, was calling for the government to extend the prepayment meter cap to more low-income households. 2018 to present: Default tariff energy price cap In the run-up to the 2017 general election, Prime Minister Theresa May made a commitment that the Conservative Party manifesto would include a policy to apply price controls to energy bills. May wrote in The Sun newspaper, saying that "the energy market is not working for ordinary working families" and that if she was re-elected she would introduce a price cap policy that would save households up to £100 each. There was pressure from other members of her Cabinet to change the policy after the election result forced May to form a minority government, but also pressure from other MPs to go ahead including an open letter signed by 192 MPs, over 70 of whom were Conservative MPs. The Prime Minister reiterated her commitment to her flagship energy policy in a speech at the Conservative Party Conference in October 2017. It was announced that the price cap, or "safeguard tariff", would be implemented by Ofgem and would cap prices for electricity and gas for the 11 million households on standard variable tariffs. The Domestic Gas and Electricity (Tariff Cap) Bill 2018 was introduced in legislation and had its first reading on 26 February 2018, following a period of pre-legislative scrutiny from the cross-party Business, Energy and Industrial Strategy Select Committee. The legislation completed its passage through Parliament on 18 July 2018 and received Royal Assent the next day. The Tariff Cap Act stipulated that the price cap would be in place from the end of 2018 until 2020, when Ofgem would recommend whether the cap should remain on an annual basis up to 2023. Ofgem would also review the level of the cap at least every 6