Prime Minister Gordon Brown has said he wants the controversy over misleading TV competitions sorted out "quickly".
Mr Brown spoke about the scandal at Prime Minister's Questions
Mr Brown told the House of Commons he would discuss the recent spate of problems with media regulator Ofcom.
"This is a very serious matter because it affects the confidence that people have in television stations," he said.
GMTV's managing director has resigned, while the BBC has suspended its competitions after some contests were found to have deceived viewers.
Mr Brown told Prime Minister's Questions he would discuss the issue with the Department for Culture, Media and Sport as well as Ofcom.
"It is a matter for these authorities to sort out and they should do it quickly," he said.
GMTV's Paul Corley said he hoped his departure would restore trust
Mr Brown's comments came after GMTV boss Paul Corley announced he would be leaving the breakfast television station.
It has been revealed that some entrants to the programme's premium rate phone quizzes had no chance because winners had already been selected.
Mr Corley's resignation was part of a series of measures he said he hoped would help "restore trust" in the company.
Also on Wednesday, Channel 4 announced details of its own "action plan designed to safeguard viewer trust".
Proposals include an "enhanced" training programme for producers and "new protocols" for its promotional materials.
Chief executive Andy Duncan said the channel was taking "appropriate steps, in partnership with our suppliers, to ensure viewers are not misled by our programmes".
He said he hoped the measures would show "how seriously Channel 4 takes the issue of trust and how determined we are to prevent our hard-won relationship with our viewers being undermined by careless or dishonest actions".
The BBC has suspended all contests on TV, radio and interactive services after an inquiry unearthed irregularities with competitions on programmes including Comic Relief and Children in Need.
Earlier this month the company was fined £50,000 for allowing a child visiting the Blue Peter studio to pose as a competition winner on BBC One last November.