Federal Labor is questioning the effectiveness of Operation Sovereign Borders after an asylum-seeker boat made it to Christmas Island undetected.
The government has confirmed that 28 asylum seekers reached the Australian territory on Monday, with their boat believed to have sunk.
Fourteen of them remain at large on the southeastern side of the island.
Opposition immigration spokesman Richard Marles says the the government has some explaining to do, especially in light of its military-style border protection operation.
"How is it with that discipline and focus that an asylum seeker [boat] has made it to Christmas Island without being detected?" he said on ABC radio on Friday.
Mr Marles said it was clear Immigration Minister Scott Morrison knew very little about the incident.
Mr Morrison is expected to face an Operation Sovereign Borders media briefing later on Friday.
