We know the bit two supermarket chains dominate the Australian grocery market, and engage in fierce price-cutting campaigns to increase their share.

But one grocer is saying it's all just spin.

Gary Grienke and Mal Meninga run fruit and vegetable store Meninga Fresh on Brisbane's Southside. And we all know the rugby league State of Origin legend loves nothing more than going into battle.

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Together Meninga and Grienke are declaring war - a fruit and vegetable battle against the competitor next door - Coles.

They're calling out the supermarket’s campaign of slashing fruit and vegetables prices by half.

“The public needs to know this isn't about prices, this is a dead set fruit and vegetable con,” Grienke said.

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“They've put tomatoes on special for less than $3 a kilo, but here I am selling them at 89 cents a kilo,” he said.

And Grienke says he's not even advertising his tomatoes as a special. But he is worried that customers are believing the hype of his neighbouring supermarket, and their super special signs, and walking out without checking the prices.

“People do get sucked in to this sort of advertising, because it is good advertising,” he said.

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Across a trolley of twenty items Grienke’s fruit and veg is a whopping $23.61 cheaper.

“My challenge to the supermarkets is to be genuine to the customer. Full stop.”

The big differences are on items like yellow peaches, broccoli and onions.

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The strange thing is that Grienke says he's not even cutting his prices to beat Coles - not yet anyway. But he knows how powerful the majors can be.

Two years ago he took on Woolworths with his shop on Brisbane's Northside, and he lost. The shop forced to close, and now his battle is against Coles, and he's on the attack with some big specials.

He’s selling pumpkins for nineteen cents a kilogram. At Coles the same thing is $2.98 a kilogram.

Grienke is now calling on all independent fruiterers to do the same.

“The independents need to fight hard, and the public need to get behind them. Otherwise you won't see independent fruit and vegetable stores for much longer,” he said.

grab supa fruiterer 16.59 We have to keep it up. We've got to keep the people coming, keep teh people happy. And we will keep it up because of that.

Fruiterer Peter McPhee is answering the call. He too is taking on all the big supermarkets, and especially his nearby Woolworths, slashing his prices today.

Nineteen items bought at McPhee’s store today was $20.17 cheaper than at the nearby Woolworths.

“I'd be horrified if we weren't cheaper. We're always going to be cheaper on the shelf lines,” McPhee said.

Independent Senator Nick Xenophon has been calling for tighter regulations on the major's for years, and especially to the claims they make.

“You need to ask whether these are genuine discounts, and whether prices on other items in their supermarkets are going to go up,” he said.

“It's obviously a marketing ploy, but you need to ask whether these discounts are genuine, whether they're long term.”

Coles says Meninga Fresh is playing its own games by lowering prices just for our cameras, and then raising them again.

According to Coles, as recent as this afternoon, in their own price comparison, they were cheaper than Meninga Fresh on at least seven items in our trolley.

Grienke says they deliberately sought out dearer varieties. Coles was, however, cheaper on all its super specials.

Meanwhile Woolworths says claims of massive price cuts should be critically examined.

But for Grienke this is just the start, and he says customers need to be on high alert, no matter who is making the claims, and assess each item.

“We're going to have a real crack at making sure that they don't get us a second time,” he concluded.