Channel 4 and Sky have denied responsibility for confusing viewers over the availability of new digital channel More4.
Some satellite viewers found their More4 signal blacked out
Channel 4 said More4 would be available "free from launch in more than 15 million UK TV homes via Freeview, Sky Digital and digital cable".
But viewers cannot receive it on Sky's satellite service without subscription.
Channel 4 said the decision was down to Sky. Sky said Channel 4 had been aware that it would require a subscription.
More4 made its debut on Monday night with a showing of a satire on David Blunkett.
Digital satellite viewers will need to take out a subscription with Sky to receive the channel.
Most digital satellite users subscribe to Sky Digital, and would get More4 - as well its sister station E4 - as part of their basic package.
But others can watch digital satellite - which offers 120 channels without charge - for free, if their subscriptions had lapsed or if they had taken up Sky's "Freesat from Sky" package.
Freeview users - who watch via their TV aerials - get both More4 and E4 for free.
A Channel 4 spokesman said that under the contract it had with Sky to broadcast its channels on digital satellite, Sky had the right to choose whether or not to make More4 a subscription service.
"More4 is positioned as a public service channel which we are providing for free and for which we are receiving no subscription income," he said.
"We would obviously like it to be made available to the widest possible audience. However, contractually the decision to place More4 in a basic subscription package rather than on their Freesat service is one that lies in Sky's hands."
More4 launched with a satire on David Blunkett's private life
A Sky spokesman said: "More4 is a subscription channel on the satellite platform under the agreement that exists between Sky and Channel 4."
Sky has no plans to alter that agreement, the spokesman said.
Broadcasting watchdog Ofcom said it received 18 complaints from viewers concerning the availability of More4.
A spokesman would not say whether the watchdog would act upon them, but added: "Ofcom takes each complaint on its merits."
'Disgraceful and wrong'
Viewer David Williams, from Stafford, e-mailed the BBC News website to say he could not pick up the service.
"Why has Channel 4 made More4 a subscription channel on digital satellite? Viewers have been told for a long time it would be free to air - now we are told you have to subscribe," he said.
"It's disgraceful and wrong for Channel 4 to mislead the general public and the media."
Steve Watson, from Bridlington, said he had checked More4's website on Monday morning and had been told it would be "available free-to-air on Freeview, Sky Digital and digital cable".
But he said it had changed by Monday evening.
"What changed in the intervening few hours? Like many others I can't receive Freeview. The Freesat service is my only option to 'go digital' without buying a subscription I don't want and don't need. What a farce."
On Wednesday Channel 4 said: "The marketing for More4 has only ever specified the platforms on which More4 would be available.
"It was never suggested that it would be available for free on all of those platforms."