The Green Party is calling on the Government to ramp up diplomatic efforts to bring home the New Zealand anti-whaling protester arrested in Japan.
Peter Bethune is in custody in Japan, after boarding a Japanese whaling ship in the Southern Ocean in February and attempting a citizen's arrest of the vessel's skipper.
He has been charged with trespass and. if convicted, could face up to three years in jail.
The Green Party says the Government should use all available diplomatic channels to bring Mr Bethune back to New Zealand.
But Foreign Affairs Minister Murray McCully says the Government cannot interfere in another country's judicial process.
He says he is satisfied that Japanese authorities are co-operating with New Zealand consular staff in Toyko.