Wellington-based technology company Snapper is rejecting allegations it has failed to meet commitments to Auckland's new public transport ticket system, due to be rolled out by December.
Auckland's transport agency wants millions of dollars in compensation from Smapper company over repeated delays to the new electronic card.
The agency and company Snapper also disagree over whether the integrated ticketing system will be ready as agreed by the end of November.
Auckland Transport and the New Zealand Transport Agency have jointly developed a single electronic payment system called HOP.
The city's biggest operator, NZ Bus, uses rival technology which it promised in a contract that it could adapt to the HOP system.
A leaked letter from Auckland Transport lawyers says the agency will seek more than $2 million for contract breaches.
It also says Snapper has admitted it will miss the 30 November deadline.
Snapper chair Rhoda Philippo, however, says it will be ready on time.
"Auckland Transport are seeking asssurances from Snapper that we can provide a compliant system - and we can."
Ms Philippo says the alleged contract breaches listed in a letter from Auckland Transport's lawyers have not been clarified and include errors.
She says the company is seeking legal advice.
A final response by Snapper to the letter is due on Tuesday afternoon but any decision by the agency could be days away.
Auckland's Chamber of Commerce chair Michael Barnett says further delays are unacceptable and the possibility that commuters will end up with two separate systems is nonsense.
Auckland mayor Len Brown agrees it is critical for Aucklanders to have one integrated system.
Mr Brown says he will speak urgently with Auckland Transport and Snapper on Tuesday to make sure they will deliver on promises to have the technology in place by the November deadline.