Some content from Coronation Street will have to be vetted once it moves into its new timeslot at 5.30pm.

TVNZ announced yesterday that MasterChef Australia would be screened at 7.30pm on weeknights, taking over the British soap's time slot.

The move has outraged fans, with some disgruntled viewers creating a Facebook page and a petition calling for the programme to remain where it is.

Coronation Street would move into a 5.30pm timeslot, five days a week, to make way for MasterChef.

Some of the more adult content might have to be removed as a result, a TVNZ spokeswoman said.

"We have to exercise great caution around challenging material," she said. "Our expectation is that we will have to make very few changes to Coronation Street."

Programmes that screen at 5.30pm have to be rated for a General audience, while programmes rated PGR, which stands for Parental Guidance Recommended, could screen between 9am and 4pm, and between 7pm until 6am, according to the Broadcasting Standards Authority.

More than 2500 angry Coronation Street fans have signed a petition voicing their outrage at TVNZ's proposal to move the popular show out of primetime despite it being one of the most watched shows on TV.

Coronation Street had been screening for an hour, twice a week on Tuesdays and Thursdays and MasterChef Australia had been screening prior to the 6pm news.

TVNZ said MasterChef was extremely popular in the final weeks of last year's competition, and it wanted to move it to a more popular timeslot to accommodate it.

But ratings on the website Throng, show that Coronation Street is still one of the most-viewed shows on television.

Its last ten episodes had all been in the top five viewed shows of the day out of all TVNZ and TV3 programmes, according to the website.

It was also often the most watched show in the 7.30pm to 11pm time bracket.

Coronation Street has nearly double the amount of viewers as MasterChef does, according to TVNZ's own ratings.

While MasterChef has an average audience of 249,000 people aged over five, Coronation Street has an average of 525,000.

But a TVNZ spokeswoman said while ratings were a factor "they're not the key driver here".

Both shows received the same average audience when the numbers were evened out to reflect the different time zones, she said.

The move has outraged dedicated fans, who say they won't be home in time to watch it or would be making dinner.

More than 500 comments were posted on Stuff yesterday, many saying that there were already too many cooking shows on television.

An online petition and a 'Keep Coronation Street at 7:30 pm' Facebook page were also set up yesterday.

The petition had more than 1800 signatures this morning and the Facebook page was 'liked' by more than 200 people.

"How dare the programmers presume that Coro Street is just watched & enjoyed by retired old people who are home around that time," one person wrote on the petition's comments section.

"Like many people I know who just love Coro, I work long hours, & the best nights of the week are when I can sit down & relax for an hour to enjoy this classic programme.

"Like many working people, and of course anyone even preparing a meal at 5.30pm, this proposed timeslot change will make watching this wonderful soap impossible. As for another Masterchef programme...forget it, I will not be watching that."

Close to 9000 people have voted on a Stuff poll, with 70 per cent saying TVNZ should not put MasterChef in the 7.30pm timeslot.

But a TVNZ spokeswoman said the final episodes of MasterChef last year were extremely popular, with the final drawing in more than one million viewers.

"This is not driven by ratings," she said. "MasterChef is designed as a show aimed to be aired in primetime and last year when we put it out in primetime it did incredibly strongly and we think this year it could do even better."

There had been a "high number" of calls to TVNZ in response to the move, many coming from disgruntled Coronation Street fans, but some also said they were looking forward to the change.

TVNZ was not surprised at the level of interest, the spokeswoman said.

The schedule change would take effect from October 17 and was in place not only to work around MasterChef's popularity but to also fit in coverage of the Rugby World Cup and the General Election.

MasterChef would end in early November but Coronation Street wouldn't necessarily return to the 7.30pm timeslot, the spokeswoman said.

"We're keeping an open mind and we hope our viewers do the same."

She said Coronation Street fans would now have an extra half an hour of the show each week and would also have the opportunity to watch the omnibus, which would include all of the week's shows, on Saturdays.