Labor minister Tony Burke reaffirmed the government's commitment to boat turnbacks, saying the "policy doesn't change".
It follows the second asylum seeker vessel in a month to be intercepted near Christmas Island, with the new arrival occurring on Thursday.
The first boat from Sri Lanka was intercepted by the border force on May 21.
Mr Burke, who briefly served as immigration minister during the Rudd government, said the "one good thing" the previous coalition government delivered was "how to handle this issue".
"People who try to come by boat get turned around and sent back," Mr Burke told the Nine Network on Friday.
"When they (coalition) came up with a way of being able to do the turn backs, it was a good idea. We back it."
Nationals Leader David Littleproud said the second boat arrival was due to people smugglers seeing a "chink in the amour" of the nation's borders.
"This is a real test for this government, about whether they have the ticker to stand up to people smugglers," he said.
"If they (government) don't hold the line, and continue on the trajectory that we need as a government, then you will see boats coming ... lives lost and you will see billions of dollars spent in trying to fix this problem."
