Ed Miliband yesterday promised a 20-month freeze on energy bills – saving families £120 a year – as he told voters sceptical about Labour: “Britain can do better than this.”

In a confidently-delivered conference speech, the Labour leader pledged to introduce the freeze within weeks of victory in May 2015, to help tackle a “cost of living crisis”.

The eye-catching initiative – costing the unpopular energy giants £4.5bn – would be followed by a radical overhaul of the energy market, to end rip-offs and soaring bills.

Mr Miliband told the party faithful: “The next Labour Government will freeze gas and electricity prices until the start of 2017.

“That’s what I mean by a Government that fights for you, that’s what I mean when I say: Britain can do better than this.”

The last phrase was one that Mr Miliband repeated 18 times, as he sought to ram the message that the coalition has failed on the economy – and is failing on living standards.

He accused David Cameron of planning a “lap of honour” after the recent economic upturn, despite the slowest recovery for 100 years, with most people becoming worse off.

During the speech, Mr Miliband also pledged Labour would:

  • Build 200,000 homes a year, by 2020 – with stronger powers for local councils to get tough with “land hoarding” developers
  • Bring together the NHS with “all the care for the elderly” – apparently backing plans to merge the health service and social care.
  • Give 16 and 17-year-olds the vote in general elections.

However, it was the move to freeze gas and electricity bills that grabbed the attention, with Labour insisting it had clear legal advice that it had the power to act.

Aides pointed to figures suggesting wholesale prices plunged by 45 per cent in 2009, yet bills fell by only five per cent – hiking annual profits for the energy giants to £4bn.

Mr Miliband’s Government would also introduce much simpler tariffs modelled on ‘phone bills – with just a standing charge and a cost per unit used.

Labour shrugged off any suggestion that energy investment would be harmed, insisting there was no link between higher profits and investment in new production.

The freeze would save households – who have seen bills rise by £300 since 2010 - £120 a year and the average business £1,800 a year.

If the energy giants attempted to hike bills before the 2015 election – to avoid the cap – the freeze could be backdated, Labour warned.