Opposition Leader Tony Abbott has warned the government it can't make commitments at a regional summit on people smuggling while it's in caretaker mode.
Immigration Minister Tony Burke will attend Tuesday's one-day summit in Indonesia to discuss regional solutions to the asylum seeker issue plaguing Australia and its neighbours.
"I'm not going to object to ministers going to this particular forum but frankly they cannot make commitments on behalf of Australia without getting the agreement of the opposition in writing," Mr Abbott told reporters on Monday.
He said Labor was "pretty desultory in its observance of the caretaker conventions", which came into effect in early August when the parliament was dissolved to make way for the September 7 election.
Greens Senator Sarah Hanson-Young is disappointed her request to attend the summit was rejected.
"The government hasn't taken the opportunity to open the summit up to other voices within the Australian parliament," she told reporters in Canberra.
"I think that it's a great pity."
Meanwhile, another asylum seeker boat has arrived at Christmas Island.
The vessel carrying 209 people sent a distress signal on Sunday morning and was located in Indonesian waters by HMAS Parramatta before being escorted to the island for processing.
Mr Abbott was asked if he agreed Labor's PNG solution could be starting to stem the flow of boat arrivals from Indonesia, given it's the first vessel to be detected for days.
"There'll be surges and there will be lulls, there always have been," he said.
"The problem is that this government's so-called PNG solution is already overwhelmed by the tide of boat arrivals since (Prime Minister Kevin) Rudd first made the announcement."
