HIGH-PROFILE gardening guru Peter Cundall has been arrested.

Mr Cundall, who is The Weekly Times Gardening writer, was arrested outside the Tasmanian Parliament yesterday as he joined about 50 anti-pulp mill protesters.

The Hobart Mercury reports the protesters from Pulp the Mill were demanding a Royal Commission into the pulp mill assessment process.

After refusing to leave the front steps of Parliament House, police were called to force their removal.

About 10 officers formally arrested the protesters for failing to abide by directions of the police.

Mr Cundall said he had never been arrested in his life.

"I feel almost desperate about the situation in Tasmania now," Mr Cundall said.

"There is no question that everything we love about this state – including its democracy, law, the effect on the judiciary – all these things are being destroyed."

Pulp the Mill spokeswoman Lucy Landon-Lane said getting arrested sent the clear message to potential investors that the Gunns pulp mill proposal in the Tamar Valley did not have community support.

"The unhealthy relationship between the Tasmanian Government politicians and Gunns has left us with no other option but to take this stand," Ms Landon-Lane said