Westpac Stadium chief executive Shane Harmon says there will be signs telling people they're buying low-alcohol beer.

The fact most beers on sale will be low-alcohol isn't publicised to those who've bought tickets.

Mr Harmon says that's because their special licence for alcohol is granted "quite close to the event, so tickets are on sale well in advance of that".

"As part of that special licence, we now provide a full range of beverages from 2.5 percent to 4 percent. It's about giving people choice and giving people the ability to pace themselves during the day," Mr Harmon says.

He didn't believe it was a huge inconvenience for people to get to the Pavilion bar, which is on the same level as the concourse that leads into the stadium entry gates.

But veteran concert promoter and former long-time Sevens attendee Phil Sprey says the decision is "treating people like they're idiots and that they're simple".

He predicts once people find out most of the beers are low-alcohol, it'll be spread widely on social media.

"If that happens on the morning of day one of the event, you know what's going to happen on day two is people will start pre-loading.

"They could be making it a worse issue by trying to find this bizarre way of trying to solve an issue," he says.

But Mr Harmon believes the difference between the strengths of Bookbinder and Mac's Gold is "splitting hairs".

"The 3.5 percent is a well-known and well-loved craft beer in Bookbinder".

Mr Sprey, who has promoted a number of concerts in Wellington including Elton John and Bon Jovi, says he is a "big rugby fan" who used to enjoy the carnival atmosphere of the event.

However, he believes it has "gradually spiralled down" because of several changes to the event which is reflected in attendance numbers.

Over the years, the date had changed from Waitangi weekend, police became "overzealous", and organisers tried to give the event a family vibe - none of which worked, Mr Sprey says.

But the event can still be salvaged if parties, including police, the city council, the stadium and New Zealand Rugby, work together, Mr Sprey believes.

"[If they] actually sit down and talk openly about it and not try protect their little corners, there's an opportunity to put it back on the rails."

New Zealand Rugby insists it's expecting around 15,000 punters at the event on Saturday and Sunday but a stadium insider says they're only preparing for around 8000. The stadium can accommodate 34,000 people.

Mr Harmon says this year the stadium is focusing on food vendors, with some of Wellington's top chefs and food carts catering for the event.

Tickets can still be bought at the gate.

Newshub.