The party also wants the next ACT government to better enforce existing signage laws, and commit to removing material which is in breach of the territory's billboard ban.

Having already called for a ban on roadside corflutes ahead of the 2020 election campaign, the Greens will on Friday call for further restrictions on advertising in public spaces as part of a plan to "keep Canberra beautiful".

The Greens want to ban private companies from advertising on public spaces, such as roadsides, on buses and on bus stops.

Advertising for government campaigns and community events would still be permitted, as would other material considered "public interest communication".

There is a grey area around independent schools, with Greens open to consulting with the community on whether they should be considered corporate advertisers.

The party, which is aiming to hold the balance of power in the next ACT Legislative Assembly, also wants to create a specific offence targeting the use of illegally parked vehicle to display political or commercial messages.

Debate over outdoor advertising was thrust to the centre of ACT politics at the start of the parliamentary term after Chief Minister Andrew Barr instigated a review of the territory's long-standing billboard ban.

The subsequent inquiry was inundated with submissions opposing moves to relax the ban, with just six of 166 respondents in support of billboards.

Greens planning spokeswoman Rebecca Vassarotti said corporate advertising was starting to encroach on Canberra's public spaces, despite what she described as the general public's hatred of it.

"Public space should be for the public, not for big corporations, especially in our national capital. We've got to push back before it's too late," Ms Vassarotti said.

"This kind of ubiquitous corporate advertising is bad for our wellbeing. Corporate ads can make many of us feel that we're not good enough, beautiful enough, thin enough, or rich and powerful enough."