The charity’s latest league table of energy company complaints, which measures how effectively customer complaints are dealt with by energy companies, show that Extra Energy has delivered the worst performance over the first quarter of 2016.

Across the UK as a whole there were 1,682 complaints per 100,000 Extra Energy customers over this period - the highest complaints ratio ever recorded over the course of the league table’s five year history.

SSE, Flow Energy and EDF Energy took the top three positions for dealing with complaints in the Citizens Advice table, which was published today. Flow Energy is the first small supplier to reach second place since 2015 when smaller suppliers were added to the league table.

Citizens Advice’s complaints league table of the 20 largest energy firms in Great Britain, for January to March 2016 shows:

Craig Salter, energy spokesman for Citizens Advice Scotland’s consumer futures unit, said: “Consumers across Scotland should receive the best possible standards of service from energy suppliers – regardless of the suppliers’ size.

“This league table shows that a wide range of small and large firms across the UK are providing a good service to consumers, demonstrating that size should not prevent a company from performing well.

“However, many consumers throughout Scotland continue to face a gamble when it comes to customer service. More needs to be done by suppliers to ensure that all consumers get the service they need, and these results highlight where many of those improvements need to be made.”