The BBC must be mindful of scheduling popular shows in peak times because of real consequences to other broadcasters, the creative boss of Channel 4 has said.
Former BBC One controller Jay Hunt, who is now chief creative officer of Channel 4, said it is difficult for commercial channels to compete with the BBC.
She said: "I think that the BBC needs to be mindful of the impact of their scheduling decisions because I know, because I was sat there, there is no consequence for the BBC if it doesn't work but there is a very real consequence if a big expensive, I suspect topping up more than a million quid an hour, drama doesn't work for a commercial channel."
Speaking during a debate between channel bosses at the Edinburgh international TV festival, Hunt said she thought the issue was getting better but would run and run.
The controllers were questioned about the scheduling of the return of the BBC's hit dramatisation of Poldark against ITV's new costume drama Victoria.
Kevin Lygo, director of television at ITV, said he had not complained about aggressive scheduling.
However, he admitted: "It would be best if BBC One, at the time we were playing Victoria, had some marvellous public service film about LGBT matters that would bring in ratings and similarly for the BBC it would be better if we had something boring on but Sunday night is a particular place for dramas, there is a long and esteemed heritage of costume drama.
He added: "Victoria has been a year in the making. ITV doesn't have as much stock, as much ability change to change.
"If we ran away from Poldark, I don't know what we would put there. I think there are enough viewers for both shows to succeed.
"They are both made by an ITV company so I'm either win-win or lose-lose and they will both do well.
"They are both good shows and you can record them and there are different times to watch these shows.
"Neither of us should give up the land, it would be wrong to viewers to run away and say we can't put anything we believe in against a big show.
"I think occasionally, and it is only occasionally, there is a bit of a clash of similar shows but that is life and I think it's fine."
Charlotte Moore, director of content at the BBC, said it was her duty to the licence fee payers to find the best place for the most important shows and it would be wrong to bury them.
She said: "There is an audience for both shows. Poldark is much anticipated and how fantastic there is such a rich choice of fantastic TV."
The bosses also discussed the disclosure of the BBC top talent's pay, with Moore reiterating her claim that revealing the figures would drive fees up.
Ben Frow, director of programming at Channel 5, said: "Talent brings you viewers but we seem to determined to devalue it.
"We need the jewels in our crown. I pay my licence fee, I don't need to know who earns this and who earns that."
Lygo added: "It's a mean-spirited, nosy way of looking at things and I don't think the BBC should publish them. It wouldn't get to what people want it to be. It's a waste of everyone's time and we should let it go."