The warning follows interception of a boat carrying 48 asylum seekers and four crew near Darwin late on Wednesday, the fifth boat to arrive illegally in Australia in the past week.

The Opposition says the recent surge in arrivals is because the Federal Government has gone soft on border protection.

However, Senator Evans said the Opposition was being naive in suggesting Australia could avoid a problem that the rest of the world was also confronting.

''This will be one of the great issues of the 21st century people movement,'' he said yesterday.

''We've seen record numbers of people moving throughout the world, record numbers of asylum seekers, and some sort of naive belief that Australia is going to be somehow excused from facing those problems is just a nonsense.

''This is an issue that is going to be with us for many years.''

But the Opposition immigration spokeswoman Sharman Stone said the problem had become worse because of a breakdown in immigration policy and border protection under the Rudd Government.

''It's an example of this government completely out of control,'' DrStone said.

Dr Stone said the Government was trumpeting its interception of the vessels but doing nothing to stem the flow of asylum seekers reaching Australia.

The latest boatload takes to 263 the number of suspected asylum seekers arriving in Australian territory during the past 10 days. It is the 32nd boat to have arrived in Australia since the Rudd Government took office in 2007.

Senator Evans denied the surge was the result of the Government's border protection policy.

''What we know is boat arrivals have gone up during periods when there's been severe dislocation in countries that produce asylum seekers,'' Senator Evans said.

''We've had boat arrivals in 25 of the last 33 years. This will continue to be a problem, but we are absolutely committed to doing everything we can to disrupt and prevent people smugglers.''