Sales figures for Australian supermarket chains Coles and Woolworths (ASX: WOW) will be studied over the next two weeks to measure the effect of the marketing war waged between the two in the last six months.

Outspending Woolworths by two to one, Coles still has eight more episodes of MasterChef Australia remaining to exploit its sponsorship approximated to be worth $3 million.

Coles sources say its attack on Woolworths, underscored with ''Feed your family for under $10'' ads, is producing results. Meanwhile, Woolworths has rolled out its own data showing its prices are dropping to invalidate the claim.

More is expected to come, with additional ads featuring the chef Curtis Stone and activity planned around its sponsorship of Channel Seven's My Kitchen Rules, which is set to air again in the months approaching late October when Ten's Junior MasterChef will broadcast.

Woolworths is set to release its fourth-quarter sales data next week. After five days, Wesfarmers, owner of Coles, is expected to report another increase as it announces its figures, which cover the MasterChef season.

Coles has been spending heavily behind some of its key marketing schemes. In the four weeks to July 4, the most recent figures available, the supermarket chain has shelled out more than $1 million a week on advertising alone, reaching $1.4 million in the final week. Its rival Woolworths has kept its expenditure at about $600,000 weekly.

Coles spokesman Jim Cooper dismissed claims it had lifted its budgets. ''We are not spending any more ... but we've changed the mix so that you are noticing it more, such as with the MasterChef and Curtis Stone [initiatives]. Any implication that we are ramping up our spend would not be right.''

Both companies are exhausting about 20 per cent more on advertising this year, according to data to the end of May from the Nielsen Company.