SYDNEY (Reuters) - As many as 300 asylum seekers held in Pacific detention centers may be eligible to apply for medical transfers to Australia after hardline immigration laws were eased, media reports and a government official said on Thursday.

The transfers would be the first since the government suffered an embarrassing defeat in parliament on Tuesday when opposition and independent lawmakers voted to give doctors the right to move asylum seekers to Australia for medical treatment.

“Up to 300 could be sent to Australia if they can get two doctors to sign off on their transfer,” said a government official familiar with an assessment provided by the home affairs department.

Australian media said there had been a surge in inquiries from doctors seeking medical care for asylum seekers and about 300 people would seek transfers to Australia.

Under a controversial offshore detention policy, more than 1,000 asylum seekers have been held on the Pacific islands of Papua New Guinea (PNG) and Nauru for six years after they were intercepted trying to get to Australia by boat.

It is not clear whether the 300 people would meet the requirements in the amendment, which allows the government to veto a medical transfer if intelligence agencies consider the person a security risk.

Prime Minister Scott Morrison, who is facing a general election due by May, has said the change would undermine the country’s deterrent immigration policies and encourage a new wave of refugees to pay smugglers to get them to Australia.

Opponents accuse the government of fear-mongering ahead of the election, in which opinion polls show the ruling coalition is trailing badly.

Morrison is expected to campaign heavily on the issue of border security, said Peter Chen, a professor of political science at the University of Sydney.

“All it will take is one incident where an asylum seeker breaks the law and the narrative of the election could be changed,” he said.

Refugees seeking a medical transfer will be processed at a controversial detention center to be reopened on Christmas Island, an Australian territory about 1,550 km (960 miles) northwest of the mainland.

It was not clear if the government plans to treat asylum seekers on Christmas Island, thereby denying them access to the mainland, a lawyer for a refugee advocacy group said.

Alternatively, the government might relocate those who have been treated on the mainland to Christmas Island, which would avoid the legal complexity of trying to move a person from Australia to an offshore detention center, the lawyer said.

In the past when seriously ill asylum seekers were treated on the mainland, advocates and lawyers obtained a court injunction preventing their return to PNG or Nauru.