Good Samaritans on Manus Island trying to deliver food to hungry refugees are being turned away by the military, lawyers say, warning that the men are "starving" and a full-blown humanitarian crisis is unfolding.

It comes as New Zealand's new Labour government confirmed that nation's long-standing offer to accept 150 refugees from Manus Island was "still on the table", and Opposition Leader Bill Shorten urged Prime Minister Malcolm Turnbull to accept the proposal.

More than 600 hungry, exhausted, mosquito-ravaged men continued their stand-off with authorities at the now-closed Australian-funded regional processing centre on Manus Island on Friday, refusing to leave for fears over their safety on the outside.

An injunction application is before Papua New Guinea's Supreme Court chief justice that, in the short-term, would force PNG to reopen the facility and provide food, water and electricity, and eventually transfer the men to a safe third country. It will be heard on Monday morning.