The Telecommunications Users Association (TUANZ) is making one last attempt to convince the Government to regulate the cost of switching between mobile phone networks.
In a two-to-one decision last month, the Commerce Commission's panel said Telecom's and Vodafone's plans to reduce mobile termination rates by 60% by 2014 would ensure competition took place.
Communications Minister Stephen Joyce will now decide whether to accept the commission's view, or regulate.
In a submission to Mr Joyce, TUANZ chief executive Ernie Newman argues the fees deter competition, because people are penalised for phoning other networks.
He says TUANZ's success in overturning the commission's view on access to Telecom's network gives him hope it can happen again with mobile termination rates.