Up to 900 jobs will be axed at Scottish and Southern Energy (SSE) after the company announced it is immediately suspending all its doorsteps sales.
The decision to abandon old-fashioned door-to-door selling follows a breakdown in confidence in the practice among consumers, said the energy giant.
It also comes two months after the company was found guilty of using doorstep salesmen to mislead potential customers in a case brought against it by Surrey County Council.
Commission-based doorstep selling has ceased to be an effective way to gain customers for the long term, the firm said, adding that it expected to permanently close its doorstep sales operations.
It said in a statement: "Confidence in the way companies sell energy on the doorstep, and the way in which salespeople are remunerated, is low."
It also acknowledged that energy was a "significant purchase" and the sales process required "increasingly significant" customer safeguards.
The energy supply market was evolving from the simple selling of electricity and gas to providing a bigger range of energy products and services as well, it said, adding that "engagement with customers needs to reflect this".
The statement said: "Subject to consultation with potentially affected employees, SSE believes this could result in the loss of up to 900 jobs in Great Britain, although it will be consulting with those people who may be affected about ways of avoiding compulsory redundancies. Its objective is to minimise the number of jobs lost, through the retraining and redeployment elsewhere in SSE of as many employees as possible."
Since household gas and electricity supply markets opened up to competition in the 1990s, doorstep, telephone, online, venue and partnership sales have been used by leading energy companies to encourage customers to change their supplier of electricity and gas.
In 2010-11, about 45% of SSE's total customer gains in Britain came from doorstep sales, the company said. The rest came from telephone, venue, online, direct mail and partnership sales, which will all continue.