Hackney Council spends £40,000 a year spraying weed-free streets with glyphosate, a noxious chemical linked to organ damage and infertility, which environmentalists want to see banned.

Contractor WeedFree is paid to douse the pavements with Proliance Quattro Glyphosate four times a year.

The council insists the product is safe but campaign group Friends of the Earth (FoE) has raised concerns about its effect on health, particularly on hormones, and its impact on the environment.

And last year the Chemical Regulation Directorate prohibited blanket spraying of glyphosate on hard surfaces like pavements where there is little weed growth.

Caroline Day, spokesman for campaign group Save Lea Marshes, said: “We were very shocked to discover quite how much money the council is spending spraying our streets with noxious chemicals.

“We have seen the operatives spraying the chemical on weed-free streets, without protection and without any indication to the public that this was happening.”

Paul Charman said he witnessed a WeedFree worker in Upper Clapton leaving a trail of the chemical cocktail on the pavement behind him.

Mr Charman said: “I don’t understand it. The pavements aren’t at risk of turning into forests because they have lots of street cleaners and machines with massive brushes which are going to remove any plants that are growing.”

He added: “The council has produced no evidence that there is any problem with weeds growing in Hackney’s pavements that justifies the waste of nearly £40,000 per year on harmful chemicals at a time of financial constraints.”

But Cllr Feryal Demirci, cabinet member for neighbourhoods, said in a statement that the treatment is “cost effective” and the alternatives would cost considerably more and would not work as well.

She added: “The council’s procedures relating to the use of the product have been independently assessed as safe by the Health and Safety Executive in the last 12 months.”

In June an independent laboratory test commissioned by FoE revealed traces of the chemical were present in on average 44 per cent of urine samples from people in 18 different countries.

FoE wants the European Union to urgently investigate how glyphosate is finding its way into people’s bodies and to introduce immediate restrictions on the use of glyphosate.