An organiser behind the nationwide boycott of petrol stations later this month says there are further plans to target each petrol company one by one if necessary.
Julia Roche and Donicia Cameron started a Facebook event recently, encouraging the public to avoid filling up from all petrol stations around the country for the day on October 26.
The numbers have since surged, with 15,000 people saying they will take part, and another 18,000 people expressing an interest to take a stand also.
The rise in support comes after the Prime Minister launched a scathing attack on fuel companies yesterday, saying she thinks "consumers are being fleeced" at the pump. That has prompted her to prioritise the passing of the Commerce Amendment Bill.
Julia Roche told the Herald it isn't viable that the cost of petrol keeps going up.
People have vented their frustration on the event page at the toll the rising petrol prices around the country had taken on them and their families.
Terry Murphy said whatever the petrol industry bosses say about it all being due to the cost of "crude imports" to NZ does not account for the "wild differences in price between same brand retailers in the same general area or between their stations in different places".
Angela Henwood called for the day-long event to be extended. "Every week one company should be boycotted until they pull their prices back. Keep it going for as long as it takes," she wrote.
Another called for it to happen on the 26th of every month.
Beyond October 26, Roche said they will look to focus on one petrol company at a time. And in no particular order, until change happens.
Earlier today, Ardern doubled down on her concerns, telling Newstalk ZB's Mike Yardley the "landing price" of fuel in New Zealand had gone up by 19c a litre since the start of the year, while the excise tax had only increased 3.5c. Oil firms, she said, were most definitely "profiteering".
"New Zealand's pre-tax fuel price is the highest in the OECD, and 10 years ago it was not the highest."
The Commerce Amendment Bill is set to be passed in two weeks' time.
This would give the Commerce Commission the power to conduct market studies into fuel markets to better understand how the market is functioning.
BP welcomed this announcement, with managing director Debi Boffa saying the Commerce Commission's independence would provide greater assurance to the New Zealand public and to Government that Kiwis were paying a fair price for fuel.
She said BP reviewed prices daily to ensure they were as competitive as possible.
Boffa said recent price changes had been influenced by increases to the cost of product and the weakening NZ dollar.
"In addition to this, the Government recently introduced the Auckland regional fuel tax plus increased the national fuel excise by 3.5 cents per litre [plus GST], impacting the price of fuel for motorists in Auckland and across the country."
Z Energy chief executive Mike Bennetts said he was pleased to hear the Government would expedite the passing of legislation, but disagreed that fuel companies were "fleecing" Kiwi consumers.
"Z disputes that prices are unjustifiably high, and while margins have increased from an unsustainable level in 2008 which saw fuel majors exit New Zealand, it has not increased at the level suggested."
Mobil lead country manager Andrew McNaught said the company's prices since January 2018 had not moved in line with overall increases in tax, product cost and foreign exchange rates.
"We have directly absorbed some of these increased costs into our business, and they have not been passed on to the consumer," he said.
New Zealand had a highly competitive petroleum market, with three major fuel suppliers, a specialised retailer and two supermarket chains.
"Fuel prices in New Zealand are influenced by a number of factors, including excise duties and taxes, crude and refined product costs, transport, exchange rates, local market competition, discounts, additivies, operating costs and margins," McNaught said.
Mobil aimed to offer "competitive prices while generating earnings that are used to support ongoing and future investments that are required to meet the growing demand for fuels in New Zealand".