The Bill set out the proposed new statutory role for Ofgem
, as the energy regulator, to deliver a price cap for all consumers on default tariffs, including standard variable tariffs.
Depending on the outcome of the trial, Ofgem
could roll out simplified collective switches for more customers.
said raising the cap reflected higher wholesale energy costs and costs caused by Government policies.
chief executive Dermot Nolan denied they had "caved in" to pressure from suppliers.
spokesman said: "We will now choose a new supplier to take on the customers of Future Energy.
said: "Failure to meet minimum expectations can lead to a financial penalty.
He pressed Energy Secretary Greg Clark on the issue, saying: "Do you now intend to pass legislation that requires Ofgem
to introduce a price cap or are you content now to let your firm election promise of a price cap fall by the wayside?
has been under fire for failing to take on energy giants, which are quick to hike bills when wholesale costs rise but slower to cut when prices fall.
Since 2012 Ofgem
has had powers to take action against generators in this area.
senior partner for markets Rachel Fletcher said Ofgem
was actively monitoring generators to ensure they played by the rules.
It follows research by Ofgem
that found more than half of those who had complained - 57% of domestic customers and 52% of small businesses - were not satisfied with how their supplier handled the problem.
The investigation into prolonged billing problems and complaint issues has been made by Ofgem
following its intervention in December 2013, which resulted in npower's CEO Paul Massara apologising to all the firm's customers.