Culture Secretary Jeremy Hunt took to Twitter to ask if a power cut in his street this morning was an "early reaction to Ed Miliband's speech":
The Labour leader has pledged to freeze energy prices until 2017 if he becomes Prime Minister at the next General Election.
As Ed Miliband clashes with the energy giants on prices, it is worth knowing how your expensive energy bills are actually made up.
A leading competition lawyer says an energy price freeze could leave Labour open to challenges from the courts or the European Commission.
Whether or not you approve of a state intervention into industry, there are at least two big potential obstacles for an energy price freeze.