Opposition immigration spokesman Scott Morrison says from what he's seen in Malaysia, there's no way he could support the government's plan to send recent boat arrivals there for processing.
Mr Morrison, fresh back from a visit to Kuala Lumpur, said Malaysian officials had answered questions the Australian government hadn't.
He said they had assured him the 800 asylum seekers coming from Australia would receive no special treatment.
That meant they could not attend public schools and they could not be treated at public hospitals unless they paid. Neither would they be allowed to work, exposing them to exploitation by employers or arrest for working illegally.
Mr Morrison said there remained some sticking points to finalising the agreement under which Australia will send 800 asylum seekers for processing and accept 4000 processed refugees in return.
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That includes what to do with those found not to be genuine refugees.
He said Malaysian officials were proceeding on the basis that the deal would go through, probably in early July.
But he said he was not satisfied the human rights of asylum seekers would be adequately protected.
"If there is no preferential treatment, then I know what the current arrangements are and that's not acceptable," he told ABC television.
"I don't trust the Australian government to be able to come to an agreement here that can live up to the guarantees that they say are in place."
"As an Australian MP, as an Australian, I cannot support an arrangement an arrangement that would send 800 people to what I saw in Malaysia."
Mr Morrison rejected suggestions he had only gone to Malaysia to score political points and to embarrass the government.
"I am offended by the question," he said.
"I wanted to inform myself and understand and I think it's cynical to suggest I'd have a different approach."
Mr Morrison rejected suggestions he was criticising Malaysia's human rights performance.
He said he was criticising the Australian government for planning to send 800 people to a country which wasn't a signatory to the refugee convention.
"I've been to Nauru, I've been to Nauru, and I know which is the more humane, I know which is the more cost-effective and I know which is proven," he said.
