Sian Berry wants to multiply the number of Londoners walking, cycling and using public transportation – and she has no shortage of suggestions for how to make that happen.

The Green Party candidate for mayor of London backs Crossrail, expanding Overground services, building more segregated cycle lanes and extending the so-called Mini-Holland town centre schemes to allow for more pedestrian-friendly spaces in local boroughs.

She says she can pay for the projects by hiking the congestion charge, introducing a hefty new annual tax on workplace parking spaces and scrapping plans for the Garden Bridge. And, while she is at it, Berry says she would look at banning all diesel vehicles from the capital and capping the number of private-hire vehicles to reduce congestion.

“We’re under a legal obligation to reduce air pollution as quickly as possible,” Berry told City A.M. earlier this week. “The answer has got to be more charges for people driving.”

Berry admits many of her plans are likely to frustrate Londoners – more taxes coupled with disruptions like Cycle Superhighway traffic jams – but insists there’s “no gain without pain”.

Earlier this week she drew attention when she proposed the takeover and redevelopment of London City Airport – a plan that the New Economics Foundation says could create at least 16,000 jobs: “City Airport carries just 1.5 per cent of all UK airport passengers and is therefore of negligible importance to Britain’s aviation. It will become even more irrelevant once Crossrail opens.”

But the proposals were sharply rejected not only by the airport, but also by business groups and Berry’s opponents in the race for City Hall.

A spokeswoman for City Airport said: “If Ms Berry took the time to visit London City Airport, she would see how ill-informed her views are.

“Business leaders deem the airport a major economic driver, providing vital connectivity, and generating some £750m per year for the UK economy.”

David Leam, infrastructure director at the business group London First, told City A.M. Berry’s proposals were “extremely eccentric at a time when the big debate is about how we can expand London’s air capacity to strengthen our links with growing markets around the world to be talking about closing a highly successful and key piece of infrastructure”.

A spokesperson for Tory mayoral candidate Zac Goldsmith called Berry’s plan “not realistic”, saying: “Thousands of London businesses rely on the economic activity and critical transport links that City Airport provides.”

Even so, and despite the latest YouGov survey showing Berry polling with just 3 per cent of the popular vote, she says she is unfazed by the major party front-runners, Goldsmith and Labour’s Sadiq Khan: Goldsmith is “not being the environmentalist he’s been billed as in this campaign” while Khan is courting big business and “not really presenting himself as a candidate of the people”.

“I’m the right candidate to fill that gap,” she says.