Former Greens senator and 12 others accused of obstructing traffic during Extinction Rebellion protest in 2019.

A magistrate has begun hearing allegations the former Greens senator Scott Ludlam and 12 others broke the law during a climate change protest in Sydney.

Police arrested dozens involved in an Extinction Rebellion protest in October 2019 after it stopped on one of Sydney’s busiest streets, Broadway.

Ludlam – whose nine-year parliamentary career ended during the dual-citizenship scandal in 2017 – was detained while sitting on the road. Others were arrested while lying on the ground.

The 13 people all deny failing to comply with a police direction regarding a road closure.

Each faces a maximum fine of $2,200 if found guilty.

Body-worn police camera footage played at Sydney’s Downing Centre local court on Monday showed protesters shouting, “This is what democracy looks like” as police order those lying on the ground to move on for obstructing traffic.

The rally had been authorised with the understanding it would be “free-flowing” with no stops, the police prosecutor Jamie Palmer told the court.

After an unauthorised stop outside Central railway station, the public assembly again stopped on Broadway.

Five of the 400-odd protesters tethered themselves to a pink tank that had been pulled off a parked truck as the group of the 13 accused sat or lied down on the road, the court was told.

“Muesli bars were stuck in the tank to ensure the persons were fed and watered during that time,” the prosecutor said.

At that moment, the protest was “substantially outside” the terms of the authorisation, she said.

Lawyers for the group of 13 declined to make an opening address to the magistrate Vivien Swain.

The protests came amid a week of nationwide demonstrations calling on governments to drastically reduce carbon emissions.

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