The former ABC gardening guru, 83, was among 50 people arrested at yesterday's protest against the state Government's approval of Gunns' proposed Bell Bay pulp mill in the state's north.

Protest group Pulp the Mill says the state Government's fast-track approval of the $2.5 billion project in the Tamar Valley was an abuse of power.

They want a royal commission to investigate the state's approval of the mill and the propriety of its Pulp Mill Assessment Act.

Before his arrest, Cundall said the planned mill's construction was a source of economic, environmental ''and above all democratic'' damage.

''It was a terrible thing that basically a proponent of the mill can actually make major donations to a party or both parties, and help to actually write the legislation, and it is then passed through Parliament, with the members of Parliament not allowed to oppose it or amend it,'' he said.

Protest organiser Lucy Landon-Lane said the Pulp Mill Assessment Act had been written with the help of Gunns lawyers and rushed through Parliament.

Protesters have failed in previous court action arguing against the Pulp Mill Assessment Act.

The pulp mill's construction has been approved by governments, and Gunns is in the process of finding a financing partner before work begins. AAP