Climate change protesters “crossed the line” between their right to protest and their responsibility towards the rest of the public when they caused huge tailbacks by blocking three key London roads on Monday, the policing minister, Kit Malthouse has said.

New measures will be announced to crack down on protesters who target road networks and critical national infrastructure, which “is of a different scale of damage than you would otherwise find with a normal protest”, the junior minister said.

On Monday, 54 members of Insulate Britain staged blockades at Hanger Lane, Wandsworth Bridge and the Blackwall tunnel at the height of rush-hour. On LBC radio on Tuesday morning, Boris Johnson called the group “irresponsible crusties”.

Malthouse, speaking on Sky News, said: “While we obviously all value the right to protest, there is a difference between causing disruption and causing damage. We believe that these protesters and some of the others that we’ve seen in the last couple of years have crossed the line between exercising their right but also their responsibility towards the rest of us, and something needs to be done.

“So today we’re going to be announcing a raft of new measures alongside those that are already in the police, crime, sentencing and courts bill that’s going through the House of Lords at the moment that we think will help deal with this problem, specifically recognising the disruption of infrastructure and disruption of the strategic road network is of a different scale of damage than you would otherwise find with a normal protest.”

In recent weeks, the home secretary, Priti Patel, has applied for court injunctions to stop Insulate Britain campaigners from bringing motorways to a standstill. The current fines for blocking a highway are up to £1,000.

However, breaching such an injunction is not in itself an arrestable offence. Later on Tuesday, Insulate Britain protesters are expected to visit London’s high court for a hearing about an injunction banning them from blocking the M25.

When asked on Sky why high court injunctions were not enough to bring an end to the protests, Malthouse said the “consequences step” had to follow a number of other legal steps, giving protesters a “legal loophole”.

“In the meantime, while the police can arrest these protesters and charge them for obstructing the highway, the charge at the moment isn’t severe enough that they can be detained in custody pending an appearance in court. That means that these people in particular are then free to go repeat offend, as we’ve seen.

“Eventually, given that they are as far as I can see in breach of that injunction, they will appear in front of a judge and face the wrath of that judge, but in the meantime we need to think about this particular legal loophole to give police more power to deal with this very severe disruption.”

Patel is expected to say in a speech to the Conservative party conference on Tuesday that new powers will be given to police to prevent protesters who have been disrupting motorways from travelling around the country.

She will promise new orders giving courts the power to ban individuals with a history of disruption, or where there is intelligence suggesting they are likely to commit a criminal offence, from attending particular protests.

She will also outline a new offence of disrupting critical national infrastructure. This will stop protesters from targeting power stations, media organisations or airports, Patel will say.