Labour says Fonterra's dairy products will be blocked from entering Russia until next year at least and says New Zealand Government tardiness led to the ban.
Labour Party trade spokesperson Clayton Cosgrove says Trade Minister Tim Groser has repeatedly changed his mind on whether Russia had banned Fonterra's product over the last 10 days, before finally confirming it.
Russia is a $100 million a year market for Fonterra.
Mr Cosgrove said it's clear from Russian media reports - that the New Zealand Government has not supplied Russia with the reassurances they needed over the botulism contamination.
He said the buck stops with Fonterra, but there has been 10 days of "yes, no, wait" from the Government.
Mr Cosgrove said officials should have been able to clearly provide the Russians with the evidence they needed to confirm that no contaminated product got into the market, that the product that exists now is fine and that there is no impact on the greater Russian market.
"The Russians have met with officials, they haven't got what they need, the minister wasn't sure for 10 days the status of the ban."
Mr Cosgrove said the Russian ban could have been confirmed straightaway and the minister could have then been on the phone, if not on a plane immediately, to secure that market.