The blockade was part of the "you are needed back at work" action from climate crisis group Extinction Rebellion.

Prior to the protest, which took place at 3pm, Extinction Rebellion member Angus Bylsma said the blockade was to tell politicians that they still had work to do.

"We know it will cause inconvenience," he said.

"Call it disruption if you like, but it's mild compared with what we want to prevent.

"If the stadium starts burning down during a football game, people would be pretty angry if the fire brigade wasn't called because it might disrupt the game.

"If a cyclone is coming on Christmas Day, the Weather Bureau doesn't say we won't tell them because it will disrupt their Christmas.

"Reputable scientists say the evidence is clear for all to see, planet earth is going into a period of disastrous climate change and they have shouted to "call the fire brigade". But governments don't want the disruption so they pretend they haven't heard.

"We think a little bit of disruption for our MPs is exactly what is needed and if we can get them back to work, that's great."

Tasmanian Police said it was unfortunate that seven of those arrested were under the age of 18.

"Of the twenty people arrested 13 were adults ranging in age from 18 to 79 years of age," Hobart Inspector Laurie Huxley said.

"Those people have been charged with failing to comply with the lawful direction of a police officer, and bailed to appear in the Hobart Court of Petty Sessions on November 11.

"Police have unconditionally discharged the seven youths, who will now be dealt with under the provisions of the Youth Justice Act 1997."

She said the 20 people arrested were the only protesters who did not comply with multiple police directives to disband the blockade.

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