Ofgem chief executive Andrew Wright said the reforms on fixed term deals will make the energy market "simpler, clear and fairer" and make it easier for consumers to "vote with their feet".
Mr Wright said in a statement:
In an era of rising prices it is vital that competition works as effectively as possible.
Our reforms seek to give consumers the tools they need to find the best energy deal for them and to ensure that suppliers have to treat them fairly.
Now we are looking for energy suppliers to pick up the baton and put their efforts into restoring consumer trust.
More top news
One story dominates Thursday's front pages with some newspapers printing emotive pleas to voters to keep the United Kingdom as one.
After a mild start temperatures should pick up, with the south of England seeing highs of 26C.
In Edinburgh tonight you can hear it and feel it. The buzz, the banter of the day and the thrilling sense something big is coming tomorrow.