New and expanded powers for British police took effect on Sunday, including measures targeting activists who stop traffic and major building works with protests.

Authorities have repeatedly condemned environmental protest groups, including Just Stop Oil and Extinction Rebellion, which have sought to raise awareness about the urgency of climate change by staging multiple high-profile protests at the busiest highways and roads. Their protests in recent years often caused serious disruption for motorists.

From Sunday, police will have powers to move static protests. Critics have argued the toughened laws are a threat to the right to protest, but U.K. officials say the measures were to stop “disruption from a selfish minority.”

“The public have had enough of their lives being disrupted by selfish protesters. The mayhem we’ve seen on our streets has been a scandal,” Home Secretary Suella Braverman said.

Authorities say that under the new Public Order Act, protesters found guilty of “tunnelling” — or digging underground tunnels to obstruct the building of new infrastructure works — could face three years in prison. Anyone found guilty of obstructing a major transportation project could be jailed for up to six months.

The law also makes “locking on,” or protesters attaching themselves to other people, objects or buildings, a criminal offense.

Hundreds of climate change protesters were arrested last year in the U.K. for blocking major roads and bridges. Many activists protested by sitting in the middle of the roads or gluing themselves to the roadway to make them harder to move.

The civil disobedience is a wave of direct action that has also seen activists glue themselves to famous museum paintings or throw soup at artworks to draw media attention to their cause.

Police have said it’s costly to deal with the protests and that they diverted thousands of officers from other work like dealing with crime.