Australia’s opposition leader on Tuesday promised increasingly strict measures to curb the illegal arrival of asylum seekers if his party is chosen to lead the country in elections later this year.

Tony Abbott introduced the coalition’s refugee policy just hours before Prime Minister Julia Gillard was to announce a revamp of her own party’s border protection stance.

An influx of asylum seekers entering Australian waters by boat in the last two years has become a politically hot topic. Gillard has been under pressure to toughen her party’s policy since ousting her predecessor, Kevin Rudd, who the opposition blamed for the burgeoning number of illegal arrivals.

Abbott said his coalition would prioritize offshore refugee applicants, turn away incoming boats when possible and prevent asylum seekers entering Australia if they were believed to have deliberately discarded their identity documentation.

He also reiterated his pledge to revive the so—called Pacific solution “in which Australia paid impoverished island neighbours Nauru and Papua New Guinea to keep asylum seekers in detention centres” and temporary protection visas. Under the visas, bona fide refugees would have to prove after three years that they would still face persecution if they returned to their homelands.

Mr. Rudd had scrapped both policies when his Centre-Left Labour Party won government in 2007.

Since then, more than 4,000 asylum seekers have entered Australian waters in nearly 150 rickety boats, many of them Afghans and Sri Lankans who paid Indonesian people-smugglers to ship them to Australia. They have overflowed the offshore detention centre at Christmas Island in the remote Indian Ocean, and in recent months detainees have been moved to the mainland for holding while their refugee applications are assessed.

In April, Mr. Rudd’s government attempted to slow the flow by imposing a temporary suspension on processing asylum claims from Sri Lankans and Afghans.

Ms. Gillard announced Tuesday that her government would immediately lift the Sri Lankan suspension, which had been set to expire Thursday, and assess the cases of those Sri Lankans currently in detention. The Afghan suspension was set in April for six months.

A report issued late Monday by the U.N. High Commissioner for Refugees said the situation in Sri Lanka was “greatly improved,” with Tamils no longer in need of international protection. But it urged countries to assess refugee applications on a case-by-case basis.

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