Frantic construction work is under way to erect extra tents on Christmas Island, with the government barely a boatload away from failing to honour an election promise to process asylum seekers offshore.

Immigration Minister Chris Evans has long said Darwin detention centre would be used as a backup facility if Christmas Island filled up.

On Sunday, another boatload of 58 people, believed to be Sri Lankan, pushed detainee numbers to 1,864, close to the facility’s capacity of 1,920.

The immigration department said three more tents had arrived on the island and would be “on line” by the end of the week. These would and add another 120 places for single men in the Phosphate Hill compound.

With the race on to finish construction before the next boat arrives, advocates reported growing frustration among Tamil asylum seekers there.

“The Sri Lankans are very angry,” said Dr Siva Thayaparan, the secretary for Justice and Freedom for Ceylon Tamils.

“When other nationalities like Afghans come in, they are released within four or five weeks’ time. Sri Lankans are waiting seven months.

“They spent a long time in Sri Lankan security force camps and when they escaped and came here, again the Australian government puts them into Christmas Island like a prison.”

Of 2,013 Afghans who have applied for asylum in Australia since last year, 1,181, about half, have been granted visas. But only 198, or about a quarter of 843 Sri Lankans were granted residency in the same period.

Opposition immigration spokesman Scott Morrison said the Prime Minister had created a “magnet for people smugglers” and was hiding behind an excuse of global “push factors”.

“Figures released in the UK have exposed once again that Labor’s excuses are just more spin,” Mr Morrison said. “The number of asylum applications in the last quarter of 2009 in the UK fell by 30 per cent to 4765 compared with 6775 in the last quarter in 2008.”

But a spokesman for Senator Evans accused Mr Morrison of “selectively quoting” asylum figures: “He blatantly ignores the fact that last year Afghan asylum numbers worldwide increased from about 18,500 to over 24,600. The overwhelming majority of countries that received asylum claims from Afghans saw an increase in 2009.”

The UNHCR’s Assistant High Commissioner Protection recently said claims that Australian policy changes had led to a rise in arrivals were “at odds with global trends”. – (The Age, Australia)