THE latest jousts between major grocery chains suggest we've slipped into a new phase in the retail food market that might spell even tougher times ahead for food suppliers.

Competitive tension between Coles and Woolworths has gone up a few notches in the past two weeks.

Coles got the ball rolling, saying it would move to uniform pricing across the country, reducing the use of regional pricing zones and establishing nationally equivalent prices on about 8000 lines.

Woolworths responded with a price reduction program, vowing to slash grocery prices and then sneaked in its own uniform pricing pledge, upping the ante on Coles by offering to align more than 12,000 products.

Go to any Woolworths or Safeway store or pick up a major newspaper this week and you won't miss the messages.

Uniform pricing deals was one of the areas probed in the 2008 Australian Competition and Consumer Commission grocery inquiry, which queried the ways retail prices are set region to region.

Many interested parties in the inquiry got upset over one of the basic no-brainers - if your competitor is right in your face, you'll price a product more keenly than when he isn't.

Another subtle agenda being driven home to the public is the comparative cost of living.

The promotional advertisements of both major grocery chains this week point to price comparisons with this time last year.

The rate of food-price increases over time was one of the catalysts for the 2008 review.

A drive to be seen as cheapest is now a feature of retailing in the UK, Europe, US and Japan.

The big grocery players did well to capture a greater share of household meals when things in the economy started to get tough in mid-2008.

But with the economy improving last year, mainly through the stimulus package, the food market got tougher.

With the continuing focus on "value", the major grocers held on to a greater share of the food spend.

Taking advantage of concern about the cost of living, the promotions pushed savings in the cost of meals - "feeding the family cheaper".

With the stimulus party now over, this year is tougher for most retailers, and the fight for customers' hearts and minds is fiercer. Consumers have found satisfaction with cheaper lines.

The drift during the past two years has taken enormous value out of the food chain, and put most of the pressure back on to suppliers.

The hard part is seeing how we climb out of what seems to be a spiral, even when the economy is fully back on the rails.