The lower house committee found a 1998 decision to cut the House of Assembly from 35 to 25 members has left the state with too few politicians to effectively represent voters.

Too many ministerial advisers are making decisions without accountability to the electorate, it found.

The reduction has also negatively affected debate on legislation and made it difficult for opposition parties to scrutinise the government.

Committee chair and state Greens leader Cassy O'Connor says MPs across the political spectrum who gave evidence agreed it was a mistake to reduce the number of members.

The committee, made up of governing Liberal, Labor and Greens members, unanimously recommended the restoration of a 35-member parliament

But Deputy Premier Jeremy Rockliff has poured cold water on the idea, saying increasing MP numbers was not a priority for the government.

The report also says a greater indigenous voice in state parliament is needed and has recommended the establishment of a joint parliamentary inquiry to examine the feasibility of dedicated seats for Aboriginal people.

Peak bodies, the Tasmanian Chamber of Commerce and Industry, and the Tasmanian Council of Social Services, have backed a larger lower house.

Australian Associated Press