Western Australia's opposition leader has likened a controversial state government plan to own a slice of the local crayfish industry to policy making in "the third world".

The government has proposed it take a 17.3 per cent stake in Australia's most valuable fishery while increasing annual commercial catch limits from 6000 to 8000 tonnes.

The government plan will keep back 1350 tonnes of lobster for the state to lease to the private sector for additional revenue.

The plan will keep back 1350 tonnes for the state to lease to the private sector for additional revenue.

Amid angry reactions from industry, Liberal leader Mike Nahan said the policy was, "like something you'd see in a third world country, nationalising assets."