The co-leader of the Green Party has told Sky News there should be a review of the government's net-zero transport strategy in the wake of the pandemic.
Jonathan Bartley says society has had a "glimpse" of an "alternative future" having spent months in lockdowns using fewer emissions and travelling less.
Decarbonising transport is critical to reaching the UK's legally-binding target of generating net-zero emissions by 2050 to help tackle climate change.
And Mr Bartley said the COVID-19 crisis makes the case for Britain's biggest infrastructure project - the new HS2 high speed rail network - "even weaker".
He said: "I think the pandemic should put the whole government transport policy in doubt.
"When you look at the £27bn road building programme and when you look at the freeze on fuel duty, these are things we should be really questioning in the light of the pandemic, as well as HS2.
"I think there's a glimpse of an alternative future - a better future that we can have.
"And we know - and the public are very aware - that we're going to have to live with COVID for a while.
"There may be future pandemics coming down the line because of our exploitation of nature, so what we need to focus on is resilient local economies."
The new high speed rail line will eventually link London and the north of England and the first phase of HS2 between London and Birmingham is due to open between 2029 and 2033.
The government is telling us to switch to public transport to cut emissions and is backing HS2, but the network's environmental benefits and the impact of building it are hotly disputed.
Officially, the Green Party is against HS2, believing it's not needed.
But even within the green movement there are divisions about the best way to net zero.
Some members believe rail decarbonisation has to be part of the UK's climate solutions.
Sam Easterby-Smith has been a member of the Green Party for five years and is standing in local elections in Manchester later this year.
He is part of a small group which calls itself Greens For HS2 and describes labelling HS2 as "ecocide" as "really unhelpful".
He said: "Greens For HS2 are worried that the argument against HS2 is distracting from where our real problems lie, and those are in road building and aviation. We need green infrastructure far more than we need new roads.
"We need to look at the practical steps that we can take to really affect change."