Natural gas supplies are provided by Corona Energy and electricity supplies are provided by British Gas Trading Ltd and EDF Energy. The energy costs for the parliamentary estate for the last five financial years were: £million 2008-09 3.743 2009-10 3.986 2010-11 4.107 2011-12 4.353 2012-13 4.653 It is not possible to provide a breakdown of the energy consumption between the two Houses. The House Authorities use the Government Procurement Service (GPS) framework to provide energy suppliers. This is a competitively tendered process. The House policy is to use public sector frameworks where these are available as they have tested the market and greatly reduce the time taken and resource incurred by the House. The Commission has not recently considered changing the energy supplier to the Estate as the House Authorities use the public sector frameworks to identify energy suppliers. In order for the House to change its suppliers it would first need to give six months' notice to the GPS that it was terminating the use of their framework service.