Apple accused three of Australia’s largest banks of acting as a cartel, and “a hard core breach” of the country’s competition law, following a plea they made to negotiate collectively with the iPhone maker.

The comments came in a strongly worded response to the Australian Competition and Consumer Commission (ACCC).

Three of the country’s big four banks (National Australia Bank, Commonwealth Bank of Australia and Westpac) wanted to deal with Apple together when discussing the terms for getting payment apps installed on devices. The fourth, ANZ, has already struck a deal with Apple.

The applicants rely on “innuendo and misstatements” to support their submission, said Apple.

The banks have little insight into Apple Pay or Apple’s terms, the letter added. In fact, one applicant bank even refused to sign a confidentiality agreement which would have enabled a preliminary discussion about participating in Apple Pay, the US company said.

Instead, the banks want to negotiate with Apple collectively. The goal is to force Apple and other third-party wallet providers to accept their terms, enable them to charge users who choose Apple Pay and force the US firm “to undermine the security of its payment system”.

The last claim is because, Apple says, the banks want access to the NFC antenna on devices.

Apple admits it has struggled to reach agreements with the three banks (and failed), which view the newcomer as a competitive threat.

“These banks want to maintain complete control over their customers,” Apple laments elsewhere in its letter.

This is the most resistance Apple has encountered in its international rollout of Apple Pay. Australia’s banks are experienced with contactless payments and confident of their technical competence, and clearly view Apple as a potential threat.

Apple’s letter was dated a week ago, but only came to light this week.