Liberal Democrat MP Chuka Umunna claimed Extinction Rebellion has "repelled people" from supporting the group after protesters targeted London's Underground network.
The Streatham MP said the group must "re-think their tactics", with protesters climbing onto a tube trains at Canning Town station at rush hour yesterday morning.
Extinction Rebellion has staged two weeks of protests across London in its attempt to highlight the dangers of climate change.
But the activists were met with fury by commuters when targeting the Tube and were forcibly dragged from the top of the carriages.
Sadiq Khan, the Mayor of London, condemned the protests, labelling the stunt "extremely dangerous".
Mr Umunna said he support's the group's call for more Government action on climate change, but that targeting public transport would not help the cause.
He told The Late Debate: "Do it in the right way, because this is repelling people.
"The better our transport system works the more people are going to get out of their cars and use it, why stand in the way of that?"
He added: "It seems rather counter-productive to stop people getting public transport because surely they would rather people be on public transport than in cars which cough out god know how much pollution and emissions.
"That kind of action for people who are just trying to go about and do their daily work and get on with their daily lives is not bringing people to the cause."
Thousands of people have been arrested over the protests, with activists having blocked roads and targeted Government buildings over the past two weeks.
Metropolitan Police Commissioner Cressida Dick has criticized Extinction Rebellion for putting a strain of police resources.
Extinction Rebellion said it would "take stock" of the reaction to the protest on the Underground when planning further demonstrations.
But Labour MP Catherine West said the group had captured the imagination of Londoners through the protests and is helping people become more aware of climate change.
The Hornsey and Wood Green MP said: "It's really kind of captured the imagination of young people and we don't want to lose the fact that everyone is excited about this green agenda.
"We do have to remember thousands of people are dying in London because of the air pollution.
"We do have to make difficult decisions, but I would admit that some of those tactics are over the top."
Conservative MP Paul Scully, Sutton and Cheam, accused City Hall of mis-managing the protests.
He said: "The Mayor, who basically gave the green light to the protesters, was undermining the police efforts one day, but was then having the step back when he saw the effects on public transport."