In preparation for its attempt to amend the law, the Australian Greens claim that the parliament is able to legalize recreational cannabis in the country.

Based on The Guardian, the Greens––currently the minor party in Australia––have received advice from constitutional lawyer Patrick Keyzer, who contends that parliament could override state laws on the matter.

“The advice suggests that there are three commonwealth heads of power that would enable it to legalise and regulate cannabis use, with the clearest pathway via a part of section 51, which relates to copyrights, patents of inventions and designs, and trademarks,” The Guardian reported.

Under the aforementioned section 51, parliament has the power to “to make laws for the peace, order, and good government of the Commonwealth with respect to: trade and commerce with other countries, and among the States; taxation; but so as not to discriminate between States or parts of States; bounties on the production or export of goods, but so that such bounties shall be uniform throughout the Commonwealth; borrowing money on the public credit of the Commonwealth; postal, telegraphic, telephonic, and other like services; the naval and military defence of the Commonwealth and of the several States, and the control of the forces to execute and maintain the laws of the Commonwealth; lighthouses, lightships, beacons and buoys; astronomical and meteorological observations; quarantine; fisheries in Australian waters beyond territorial limits; census and statistics; currency, coinage, and legal tender; banking, other than State banking; also State banking extending beyond the limits of the State concerned, the incorporation of banks, and the issue of paper money; insurance, other than State insurance; also State insurance extending beyond the limits of the State concerned; weights and measures; bills of exchange and promissory notes; bankruptcy and insolvency” among a litany of other areas.

The Guardian reports that Keyzer’s advice centers around the part of the section pertaining to “copyrights, patents of inventions and designs, and trade marks,” saying that it empowers the commonwealth to “regulate cannabis strains as plant varieties and cause them to be listed in a schedule in respect of which the commonwealth has exclusive regulatory control.”

“We’ve been told to wait for cannabis law reform for too long, even when it’s obvious that the majority of harm caused is by policing and the war on drugs, not the plant,” David Shoebridge, a spokesperson for the Greens, said in a statement on Monday, as quoted by The Guardian.

“Recreational cannabis is enjoyed by millions in Australia and around the world, and pretending otherwise is increasingly ridiculous,” Shoebridge added. “At least 40% of Australians have used cannabis and any law that makes almost half of us criminals needs to go.”

A poll earlier this year found that Australians were split when it comes to the matter of changing the country’s marijuana laws, with 50% saying they are in favor of full cannabis reform.

Essential Research noted this was a significant increase over 2013, which saw only 25% of respondents support full reform.

The Australian Institute of Health and Welfare released a summer study that found that smoking marijuana was preferred to using tobacco.

The Greens aren’t the only party pushing for cannabis reform. Earlier this year, Australia’s single-issue Legalize Cannabis Party exceeded expectations in the country’s senate races and came close to gaining a seat.