Former Liberal leader John Hewson has unleashed an extraordinary spray at the Turnbull government over its handling of the Manus Island standoff, singling out Immigration Minister Peter Dutton as uncompassionate, and accusing both sides of politics of a “disgusting race to the bottom”.

As hundreds of refugees and asylum seekers protested the closure of the Manus Island processing centre, sparking claims of a humanitarian crisis, Dr Hewson condemned the government for “kicking the issue down the road” rather than working to find a regional solution.

And with Donald Trump warning of increased “extreme vetting” following a terrorist attack in New York on Wednesday, Dr Hewson argued the current crisis would forever taint the legacies of Malcolm Turnbull and former prime ministers Julia Gillard, Kevin Rudd and Tony Abbott.

“I’m not saying this is an easy task,” Dr Hewson told The New Daily on Wednesday.

“It’s very difficult and you are inheriting the outcome of a sequence of bad judgements and errors under both persuasions. But you’d think you’d find a solution, wouldn’t you? You think you would have focused on resettlement.”

Instead, Dr Hewson said he saw no “evidence” of anyone trying to initiate a “serious attempt at a regional agreement on refugees that includes a resettlement element”.

“[The government has] known for a long time what’s going to happen with Manus,” he said.

“They basically just sit back on all these issues and let them drift. Kick them down the road the best they can. They don’t resolve them, they get bigger and more difficult as they drift.”

By Wednesday afternoon, about 600 refugees and asylum seekers were refusing to leave the processing centre due to concerns for their safety, despite essential services being withdrawn from the PNG Navy-owned site. There has been at least one reported case of self-harm.

Peter Dutton criticised

Dr Hewson, who wrote last year that the Rudd government’s Manus solution was “always an additional, ill-conceived quick fix”, described the situation as an “obscenity”.

“To think we’ve just got ourselves on the Human Rights Council and we can’t solve a problem like that.”

He added: “I think it’s been a disgusting race to the bottom by both sides over many years.

“Every time I think they must be at the bottom, they’re not. I’ve said before the first rule of digging holes is when you get to the bottom you stop digging. Well, they’re still digging.”

Asked how he would evaluate Mr Dutton’s handling of the closure, Dr Hewson said the Immigration Minister “doesn’t come across as a very compassionate, sensitive person”.

“He takes a very hard line on these things,” Dr Hewson said. “And as far as the future leadership’s going, well, I’ve been saying, ‘If Dutton’s the answer, what the hell’s the question?'”

Mr Dutton’s office was contacted for comment.

Dr Hewson dismissed Acting PM Julie Bishop’s suggestion the issue was now the PNG government’s responsibility.

“You just can’t wash your hands of it,” he said. “It’s point-scoring and blame-shifting and no solution.”

The former Liberal leader’s comments follow a speech in September by moderate Liberal MP Russell Broadbent, who broke ranks to describe the situation on Manus Island and Nauru as “unacceptable”.

Mr Dutton said those refusing to leave the centre, “aided and abetted by so called ‘advocates’ and the Greens”, were trying to “force a change” to the policy that no boat arrivals would come to Australia.

The opposition has attacked the government’s “failure to negotiate other third-country resettlement options”, but Labor senator Lisa Singh went further, demanding the government accept New Zealand’s offer to resettle 150 refugees.

Crossbencher Cathy McGowan told The New Daily she was “open” to New Zealand as a solution to the crisis, as did Dr Hewson.

A NZ government spokeswoman confirmed to the The New Daily the offer remained on the table under the new Labour government “should Australia wish to take it up”.

NZ PM Jacinda Ardern will visit Sydney for a bilateral meeting with Mr Turnbull on Sunday.