The Energy and Climate Change Committee said the problem of such mis-selling should have been dealt with years ago.And combined with rising prices, the committee said the industry should examine whether many consumers may have paid too much for their energy.Industry body Energy UK said the rules regarding sales had been toughened.
The MPs were told that up to 40% of those who switched suppliers on the doorstep did not end up with a better deal.
They also heard evidence that vulnerable customers were particularly targeted in this way.
One firm stated that more than 70% of pre-payment customers who had recently switched to it had been won on the doorstep.
The regulator is currently investigating four of the main energy firms over the issue.
Committee chairman Tim Yeo said energy firms should stop their "Del Boy" sales tricks.