Lord Ara Darzi and Oliver Keown at the Institute of Global Health Innovation want a ban to help smokers quit and to protect children from seeing people lighting up.
Extending anti-smoking legislation in the UK to encompass a ban in parks and squares "is an opportunity to celebrate the great beacon of healthy living, clean air, and physical activity our green spaces are designed for," they write. "And, crucially, it is an opportunity to support our population - young and old - to make healthier lifestyle choices easier."