Patrons in the Fox and Ferret bar at The Palms cheer on the All Blacks during the quarter final match against France last week.

Fears of "marathon drinking" during the Rugby World Cup have not come to pass, with most early-morning fans choosing coffees over pints.

While some Christchurch bars are expecting a big turnout for Sunday's early morning semi final between the All Blacks and South Africa, a lack of numbers is causing others to remain closed.

About 30 bars across Christchurch were granted a licence to open for all the games after the Government passed a new booze bill in August allowing bars to open an hour prior to kick-off and after the final whistle.

Opponents of the bill were concerned extended bar hours could result in alcohol-related harm. The National Community Action on Youth and Drugs workers worried the RWC would become a "marathon drinking challenge" with "24-hour drinking" and fighting in the streets.

Most bars have reported they have served very little alcohol, with most people preferring to eat breakfast and have a coffee or orange juice instead.

Christchurch Hospital's emergency department has seen "no noticeable change" in the number of intoxicated people coming in.

While some, including Merivale's No.4 bar and restaurant and the Fox and Ferret expect a big turn-out, others are keeping their doors closed.

Rydges Latimer food and beverage manager Abhi Kurade said the bar had not been getting the numbers to previous matches to justify opening so early for the semi final.

"Just because of the cost involved for us to get extra staff on and the response we've had so far, it's not worth it for us to run it," he said.

"We have not had a really good response."

Kurade said he had expected more guests from the hotel to come to the bar to watch the game and have breakfast, but many chose to stay in their rooms and order room service instead.

The bar would open if the All Blacks made it to the final, he said.

Central city bar and restaurant, Fiddlesticks, is another that has decided not to open for Sunday's match.

Owner Keith Anderson said the bar regularly had 30 to 50 patrons for the previous All Blacks games, but they were not as early and he did not think people would come in to town for the 4am match.

"People are going to be at home or go to the local pub around the corner rather than a restaurant in the CBD."

The weekday games at Fiddlesticks had attracted nearby workers who had breakfast while watching the game, before heading to work.

Fiddlesticks would consider opening for the final, if the All Blacks made it that far, Anderson said.

Papanui bar Rose and Thistle owner-operator Wal Frith said the bar would open on Sunday morning, but he was not sure how many would come out for the game.

"4am is not really breakfast time and to be fair it's not really a drinking time either. We're almost opening just for the sake of opening to provide a service to people," he said.

No.4 owner Shaun Halliwell said the bar was already fully booked for this weekend's match despite the early 4am start. Last weekend's quarter final also attracted up to 200 people to the bar.

"A few people have a couple of quiet pints, but we haven't been getting people doing shots and getting stuck into it, at 8am. We haven't even needed security on," Halliwell said.

Fox and Ferret The Palms assistant general manager Lexi Byrne said she was also expecting good numbers this weekend after the bar had up to 200 patrons watching the last All Blacks match.

"People love rugby. A bar creates a much better atmosphere than watching it at home," she said.