A group of some of the country’s best-known environmental groups, including the National Trust, RSPB, WWF and Greenpeace, are today calling on the next Mayor of London to commit to making the capital a greener, healthier city.

The NGOs have drawn together 20 policy suggestions to improve London’s environment and will publish them today to mark the start of Greener London Week. Suggestions include the introduction of policies to phase out all diesel black cabs and private taxis by 2020, the launch of an energy efficiency loan scheme for London’s small businesses, and the delivery of a 10-fold increase in solar capacity across the city’s rooftops.

John Sauven, executive director at Greenpeace UK, said London has some of the highest air pollution levels in the country and the lowest level of solar deployment per household.

“Any serious vision for a cleaner London must include a plan to swap these two records around,” he said in a statement. “From transport to energy, our dependence on dirty fossil fuels is holding London back. The capital has all the resources it needs to break free from it. It’s time for the next mayor to give this cutting edge city the cutting edge power and transport systems it deserves.”

Meanwhile, Matthew Spencer, director of environmental think tank Green Alliance, said London was at risk of becoming a victim of its own success. “London is a dynamic city, but if it’s to remain a healthy place to live and work it also has to become a greener city,” he said. “London is unusual in the UK in having most of the powers it needs to make itself greener without waiting for central government. We’ve suggested 20 practical ways the next mayor can use their power on behalf of London citizens seeking a more liveable city.”

Over the next five days the London mayoral campaigns will focus on green issues, culminating in a Greener London hustings on Friday where Labour candidate Sadiq Khan, Conservative candidate Zac Goldsmith, Green Party candidate Sian Berry and Lib Dem candidate Caroline Pidgeon will present their solutions to London’s top environmental challenges.

The new package of green NGO-endorsed proposals also includes plans to increase minimum energy efficiency standards in the private rental sector to EPC level C or above by 2025, harmonise recycling and food waste schemes across London, and ban diesel vehicles in the city centre during peak times.