The ACT's politicians are being urged to allow Canberrans to legally grow up to four cannabis plants each for personal use.

Two out of the three members of a Legislative Assembly committee examining a private member's bill to legalise cannabis have recommended their colleagues support the legislation with some changes.

Committee chair, Labor MLA Bec Cody, says these changes would make the law more representative of the community's needs.

The ACT decriminalised cannabis use in 1993.

Now the committee says legislation put up by Labor backbencher Michael Pettersson should pass and allow Canberrans to grow up to four plants each, or six per household.

The government has said if the bill passes, the limit should be two plants per person and four per household, a threshold police say is low enough to ensure people aren't growing commercial quantities.

Ms Cody and fellow committee member Greens MLA Caroline Le Couteur also recommend arrangements for "cannabis social clubs" for people to join forces to grow their plants, and for plants to be allowed to be grown indoors or in greenhouses given Canberra's frosty weather and level of apartment living.

They also say if the laws pass, the ACT should intervene in any prosecutions under commonwealth law for cannabis cultivation or use.

The committee's third member, veteran Liberal MLA Vicki Dunne, did not support the legislation.

"Neither the bill put forward by the proponent, nor the proposed government or crossbench amendments will result in legislation which is fit for purpose," she said in a dissenting report.

Mrs Dunne said cannabis was a dangerous drug and its legalisation was not in the community's best interests, and that the interaction of the proposed legislation with commonwealth law wasn't properly understood.

A 2016 AIHW national drug survey found 8.4 per cent of Canberrans had used cannabis in the previous year - lower than the national average - and that the ACT had the lowest overall rate of illicit drug use.

Labor and the Greens combined hold a majority of the 25-seat Legislative Assembly.