Rampant basement development in Hampstead and across the capital has been branded a “pestilence” by the chairman of the National Trust – as he backed the idea of legislation to control excavations.

Sir Simon Jenkins, chairman of the trust since 2008, likened the trend of digging lavish underground chambers and leisure complexes to a disease while giving a talk in Hampstead.

His comments follow the collapse of a private members’ bill before Parliament, which was seeking to give councils the power to ban so-called “mega basements” and had been backed by Hampstead and Kilburn MP Glenda Jackson.

The celebrated journalist, a former editor of the Evening Standard and The Times, said: “The nuisance caused [by basements] is appalling. I get letters from all over London about them.

“They are usually totally inappropriate. This is London clay, it’s inappropriate soil to be building big structures down below.

“It is a sort of pestilence at the moment. I’d like to think the value of basements will decline and they won’t bother doing it anymore.”

Sir Simon raised the issue in a wide-ranging talk on conservation and planning to the Heath and Hampstead Society, of which he is a patron.

The former Primrose Hill resident, 71, who moved to Kensington about seven years ago, cited horror stories where houses have slumped and roads collapsed.

He backed the idea of bringing in legislation to give local authorities greater control over excavation work.

However, Westminster North MP Karen Buck’s private members’ bill to do just that recently ran out of time to complete its passage through Parliament.

The bill had been supported by Camden’s two Labour MPs, Glenda Jackson and Frank Dobson (Holborn and St Pancras).

Referring to his own neighbourhood, Sir Simon added: “South Kensington is drifting down towards the Thames on a flood of swimming pools.”

He also admitted to looking at his neighbours’ basements “with deep envy”, but said: “It’s more than my life’s worth to build one myself.”

Marc Hutchinson, installed as the Heath and Hampstead Society’s new chairman at Thursday’s meeting at St Stephen’s, Rosslyn Hill, said he would not use the world “pestilence” to describe basement projects.

The society does not oppose basements as a rule, he said, although it is concerned about specific cases, especially under terraces where adjoining properties are at risk of being damaged.

He added: “Many of our members regard the construction of basements as a nuisance and, certainly, have suffered damage to their own houses and disruption to their own lives.”

Ms Buck told the Ham&High she was considering her next step.