The federal government has launched a strident attack on the nation's largest power companies accusing them of making runaway profits as it prepares to introduce new laws that would allow it to break up energy businesses and set prices.

Federal Energy Minister Angus Taylor on Sunday used a combination of company statements and analyst forecasts to claim the three largest power companies - AGL, Origin and EnergyAustralia - would see their collective profits almost double in the five years from 2015 to 2020.

Bloomberg has forecast energy company profits to jump more than a quarter over the next two years. Credit:Dan Himbrechts

Mr Taylor said the combined profits of the companies were $1.46 billion in 2015 and would rise to $2.87 billion in 2020 based on Bloomberg forecasts.

The 2020 profit figure would represent a 26 per cent increase on the $2.6 billion in profits achieved in 2018.