Demonstrators have brought traffic to a standstill in central London as they called on the Government to do more to help households struggling with soaring energy bills.
Campaign group Fuel Poverty Action formed a blockade outside the Department of Energy and Climate Change, in Whitehall, to urge ministers to act for families facing the choice between eating and heating.
Around 50 people, including many disabled and elderly supporters, blocked the normally busy route through the capital, causing long tailbacks. They waved placards and chanted "energy for our needs, not for corporate greed", while two protesters handcuffed themselves to each other as they sat in the road.
Police were forced to divert traffic after some of the protesters refused to move from the road. The group eventually dispersed peacefully almost an hour after they began blocking the route.
Protesters had earlier taken part in a fuel bill assembly outside the department as part of a weekend of planned events called Stop the Great Fuel Robbery.
Campaigners shared their concerns about rising energy costs and plastered a poster to the front door of the Government building which read "can't pay, won't pay".
James Granger, from Fuel Poverty Action, said: "You hear some really terrible stories of people being forced out of their homes because they can't afford to keep the heating on. People are going hungry and they're freezing and they've come out to say enough is enough, they're not going to tolerate the Great Fuel Robbery any longer."
Rising energy costs have left more than six million households in the UK in fuel poverty because they spend more than 10% of their income on heating their homes, campaigners say.
It comes after the so-called "big six" energy companies - British Gas, EDF, E.On, npower, Scottish Power and SSE - all increased their tariffs this winter, citing rising costs of wholesale gas.
Mr Granger added: "The problem is the big six companies' business models depend on staying on gas. Renewable energy would be cheaper but they're refusing to make that transition because their profits depend on gas."