Retail and Fast Food Workers Union secretary Josh Cullinan said he had been told the job losses would be contained to Coles' Melbourne office.

"We had contact from Coles on the day (of the announcement) and they advised that the 450 roles are all located at their Store Support Office level, which is what they call their head office," Mr Cullinan said.

"They told us that it would not involve any store team members, so we don't expect that as a result of that change there will be any actual changes at the store level.

"Certainly, none of our members have raised concerns on that front."

Coles' announcement followed major competitor Woolworths' plan to look for significant redundancies out of its 10,000 store managers nationwide.

Mr Cullinan said last week that the Woolworths' job cuts had the potential to affect up to 30 staff in Wagga.

Coles has stated that some of the job losses would include roles that had been left vacant.

Mr Cullinan said he believed Coles' decision was related to its 'demerger' with parent company Wesfarmers, which also owns the retail chains Bunnings, Kmart and Officeworks.

"(Coles) probably ended up with a whole lot of roles they did not need," he said.

"We think the Woolworths costs were more directly related to increased wages costs from a new agreement that has come in that had to return all the penalty rates and casual loading that had been cut over the years."