The BBC’s governing body has told parents who are unhappy with the prospect of their children wanting to stay up to watch CBBC until 9pm to exercise some control over their TV habits and reach for the off button.

The BBC Trust has approved plans to extend the hours of the corporation’s children’s channel to 9pm – it currently stops broadcasting at 7pm – in a move that has divided audience opinion.

The later finish is part of plans to fill some of the space in the schedule that will be vacated when the corporation shuts the BBC3 TV channel in February next year.

“Obviously BBC3 has been a really difficult decision,” said Richard Ayre, a trustee and member of the services committee at the trust. “This was quite a difficult decision as well. This is a partnership. There is an off button.

“The BBC does its best to guarantee that what it offers to young children is safe, appropriate and suitable to see. Part of that bargain is that parents exercise some discretion about when they want their children to watch [CBBC].”

A consultation on the proposed extension of hours carried out by the trust found that the majority of respondents were ultimately opposed to the plan.

The trust said it was largely due to people who were opposed to the closure of BBC3, but Ayre admitted that public opinion specifically on the CBBC plan alone was “pretty much split down the middle”.

Responses to the consultation said the later hours would “inevitably interfere with bedtimes, ability to sleep and routines”. Another said it would “damage sleep patterns”.

A teacher who responded said the move would encourage young viewers to stay up later. “As a teacher, I already find that many children come to school tired because they have been up too late watching television,” she said.

Another added that CBBC has been instrumental in shaping children’s bedtimes and changing it would be disruptive. “Children have had routines centred around CBBC for a long time,” said the male respondent. “If the channel stays open for longer, this will cause problems not only for the children but also for the parents trying to get them to go to bed.”

Bronwen Roscoe, senior strategy adviser to the BBC Trust, pointed out that the first extra hour, from 7pm to 8pm, would be for a younger audience from six to nine years old. The hour from 8pm to 9pm would target older children.

“The public responses were split pretty much down the middle,” said Ayre. “[There were] parents who said they would value these extra two hours in helping them manage their evenings with their children. And [there were] those who thought it was not a desirable thing. At the end of the day, we had to take a view that do you allow half the audience that doesn’t want something … to prevail.”