article_snippet: Shadow energy secretary Caroline Flint said David Cameron had promised 17 times in the House of Commons to make energy suppliers automatically put all customers on energy suppliers supplier's lowest tariff.
article_snippet: During Prime Minster's Question's Time, David Cameron pledged to force energy firms to put customers on their supplier's lowest tariff .
article_snippet: Labour's Caroline Flint said David Cameron had promised 17 times  to make energy suppliers put all customers on their supplier's lowest tariff . '
highlights_snippet: In 2013 the PM pledged to force suppliers to put all customers on best deal .