this green belt is part of enfield in north london.be re—designated for housing. we can see the shard, we can see canary wharf. rob hayward's family have found here for generations. he promotes wildlife and sustainability and he thinks the green belt should stay as it is. it's the lungs of london, isn't it? i mean, you've only got to look at how beautiful this is. it's fantastic. her home, near upminster in essex, is 300 yards from the approved route of the m25. the green belt started to take shape in 1955 and has nearly always been under pressure from development. here, residents objected to the m25. there's so much pollution in london today. - it's so congested and filthy. we must have clean air around us. this green belt site in hillingdon is another target of the house—builders. in 1983, developers were looking at this site. the green belt now stretches for 40 miles from the capital. but there are those that think that we should have a much more nuanced approach to the green belt. not all green belt is as beautiful and as well—kept