Under the plan, the states and territories would hand over the power to investigate organised crime to the Federal Government.
The Prime Minister said the move would prevent gangs moving operations and assets across state borders to escape local laws.
But Mr Mischin told The Sunday Times this week he would be advising Premier Colin Barnett not to back the national plan because it would leave WA responsible for enforcing the law but unable to change it when necessary.
Mr Mischin said the Gillard Government had "ambitious objectives", but it was "not clear" how they would be workable. "It would seem that the commonwealth wishes to take over the power to make the law in this area, but leave the enforcement to WA, without the state having the power to change the law as necessary to meet any local need or changing circumstances," he said.
"WA reaffirmed to the commonwealth Attorney-General that it along with other states and territories was not interested in referring legislative power in this area."
The national laws are set to be debated at the Council of Australian Governments meeting on Friday.
Last month Ms Gillard announced a $64 million National Anti-Gang Taskforce would be created to tackle organised crime.
Under the plans, courts would have the power to declare a bikie gang or a similar group a "criminal organisation".
Police would then be allowed to use those orders to prevent club members from visiting clubhouses or holding liquor and weapons licences.
Police in every state would also be given the same powers to seize "unexplained wealth", including cash, cars and houses, from criminals.
WA already has anti-association laws in place which give the Police Commissioner and the Corruption and Crime Commission the ability to declare groups criminal organisations.
Federal Attorney-General Mark Dreyfus said this month it was vital state and federal law-enforcement agencies had the powers to break up gangs and seize their assets.