British Gas owner Centrica has announced it will cut 5,000 jobs this year.
New CEO Chris O'Shea said he regretted "difficult decisions" that had to be taken as he tried to slim down the ailing company, which trades north of the border as Scottish Gas.
More than half of the job losses will come from the business's leadership roles, as Centrica revealed it would strip out three layers of middle managers, in a bid to cut bureaucracy.
O'Shea said: "I truly regret that these difficult decisions will have to be made and understand the impact on the colleagues who will leave us,"
"However, the changes we are proposing to make are designed to arrest our decline, allow us to focus on our customers and create a sustainable company."
Although it is still by far the biggest energy supplier in Britain, British Gas has been squeezed by increased competition in recent years.
The company has lost around half its earnings in the past decade, as smaller suppliers chipped away at its market share, from a quarter in 2013 to 19% today.
