Protesters who block roads will face up to 12 months behind bars from Wednesday as new criminal offences for disruptive demonstrations come into force.
The measures in the Public Order Act, which received royal assent on Tuesday, will give police the powers to stop disruption at major sporting and cultural events this summer in England and Wales, the Home Office said.
A new offence of “interfering with key national infrastructure” such as oil refineries, airports and railways could carry a maximum sentence of 12 months in prison and an unlimited fine.
Officers will also be able to search protesters for padlocks, glue and digging tools, with people intending to use them to cause disruption also facing criminal charges.
The tougher penalties are aimed at curbing the guerrilla tactics used by groups such as Just Stop Oil, Insulate Britain and Extinction Rebellion.
Home Secretary Suella Braverman said: “The public shouldn’t have their daily lives ruined by so called ‘eco-warriors’ causing disruption and wasting millions of pounds of taxpayer money.
“The selfish minority must not be allowed to get away with this. We are giving our police and courts the tools they need to stop this chaos and I back them in making full use of these powers.”