The coalition government has already cut the annual migration program to 190,000 places from more than 300,000 under Labor.
Mr Dutton says if the government has to bring it back further, they will do so.
New Liberal senator Jim Molan used his first speech in parliament (Wed night) to warn Australia may not be able to handle any more legal migrants.
The retired major general says Australia is approaching it's migration limits, if it hadn't already exceeded them.
