Breakfast broadcaster GMTV was yesterday hit with the largest financial penalty ordered in the wake of the TV competitions scandal when it was punished with a £2 million fine.

And the company's relationship with Birmingham business Opera Telecom was described by Ofcom as "irresponsible and negligent".

The TV regulator ordered its biggest financial sanction on a broadcaster after it emerged GMTV had charged viewers to enter competitions even though they had no chance of winning. The regulator said the breaches, which took place between August 2003 and February 2007, amounted to "gross negligence" and the "widespread and systematic deception of millions of viewers".

Ofcom said GMTV staff, plus personnel from competition phone line provider Opera Telecom, operated a method which saw 15 finalists picked between 6am and 8.30am and the remaining five after 9am when lines closed, putting callers between 8.30am and 9am at a disadvantage. GMTV staff were "complicit", even though they may not have understood the implications, Ofcom said.

It said GMTV's relationship with Opera Telecom - told to pay £250,000 earlier this week - was "irresponsible and negligent". GMTV said in a statement: "GMTV accepts Ofcom's judgment and takes full responsibility for the breaches of the Ofcom Broadcasting Code."

It is offering refunds to affected viewers and has made a £250,000 donation to ChildLine.