Council workers in Kirklees have called for a temporary ban on the use of a controversial herbicide that has been linked to cancer.

Around 100 gardeners are employed in 16 teams within Kirklees Council’s gardening service. All have been trained to use glyphosate, a key ingredient in the best-selling weedkiller Roundup.

Three years ago glyphosate was described as “probably carcinogenic to humans” by the World Health Organisation. The naturalist and TV presenter Chris Packham has also been critical, describing it as “toxic.”

Gardening staff working across the borough have raised the use of glyphosate with the council as a cause for concern.

Branch secretary of Kirklees Unison, Paul Holmes, said around 80 members could come into regular contact with the chemical.

“The council does use glyphosate and considers it to be safe. However we believe Kirklees should stop using it until a proper investigation is done and we get the full story.”

Andrew Aldwinkle, regional organiser for the GMB union, said: “GMB nationally are calling for a ban on the use of glyphosate.

“We will be raising this at the highest level at the council too.”

The unions’ stance has been backed by the Soil Association, which said local authorities should look into alternative options “and stop all use of weed-killers containing glyphosate.”

A spokesman for Kirklees Council confirmed the authority’s use of glyphosate as an approved and legal substance.

The chemical was recently at the centre of a landmark court case in the US with Roundup manufacturer Monsanto ordered to pay $289m to a groundskeeper, Dewayne Johnson, who said his terminal cancer was caused by regular exposure to glyphosate.

Plaintiff Dewayne Johnson, facing camera, hugs one of his lawyers after hearing the verdict in his case against Monsanto at the Superior Court of California in San Francisco on Friday, Aug. 10, 2018

The chemicals giant has argued that glyphosate is not carcinogenic. It is fighting the court’s decision.

In 2015 the World Health Organisation’s International Agency for Research on Cancer stated that glyphosate was “probably carcinogenic to humans.” Since then, two EU agencies - the European Food Safety Agency and the European Chemicals Agency - have concluded that it is safe.

The potential harmful effects of the chemical continue to split opinion. Emma Hockridge, head of policy at the Soil Association said the use of glyphosate by farmers, gardeners “and many, if not most councils”, to clear weeds from fields, gardens, parks and public places, was “of concern.”

She said studies by the International Agency for Research on Cancer (IARC) showing the clearest link between glyphosate and certain human cancers looked at operators using glyphosate herbicides.

Following the US court case some British retailers said they were reviewing their product ranges.

A B&Q spokesperson said: “B&Q has been reviewing its garden care and maintenance range since 2017 and this review is on-going.”

Leeds Road Retail Park. B&Q.

The company said its review was already in progress and was not a direct reaction to Mr Johnson’s case.

The National Farmers Union said it was aware of the ruling but pointed to the opinions of independent regulatory bodies around the world.

A spokesman said: “The European Food Safety Authority (EFSA) and the European Chemicals Agency (ECHA) have looked at all the scientific evidence and concluded glyphosate is safe to use.

“But their conclusions have been ignored and their credibility has been undermined.

“Glyphosate reduces the need to use other herbicides, it helps to protect soil and cut greenhouse gas emissions by reducing the need for ploughing, and it enables farmers in this country to grow crops that help produce safe, affordable, high quality British food.”