The prime minister has been urged to invest £5.5bn to 'level up' access to urban green spaces by a coalition of councils, city leaders and charities.
New research by Vivid Economics and Barton Wilmore shows that a £5.5bn commitment to green infrastructure could deliver £200bn in physical health and mental wellbeing benefits.
It reveals that 295 deprived neighbourhoods are 'grey deserts' with no accessible green space or trees.
Local councils, the National Trust, the Mayor of the West Midlands, Sustrans and Create Streets have now written to Boris Johnson to make the case the greening the country's greyest urban communities over the next five years.
John Haxworth, partner at Barton Willmore, said: 'The value for money of investing in these programmes is incredibly high, but it has been hidden because we haven’t had a way of measuring the benefits that greenspace brings to peoples’ lives.
'Every £1 spent on levelling up existing parks in deprived areas will generate £100 of benefits across 30 years. Investing in creating new parks and greening urban areas would bring a return of at least three-to-one in the same period – almost twice as much as Crossrail or HS2.'