Christopher Portier advised the International Agency for Research on Cancer, part of the World Health Organisation, which declared that glyphosate was a probable human carcinogen

A scientist who advised a United Nations agency to classify the world’s most widely used weedkiller as carcinogenic received $160,000 (£121,500) from law firms bringing claims by cancer victims against the manufacturer.

Christopher Portier advised the International Agency for Research on Cancer (IARC), part of the World Health Organisation, which concluded in March 2015 that glyphosate was a “probable human carcinogen”.

He did not declare his links to the law firms in a letter to the European Commission urging it to accept the IARC classification.

The commission is debating whether to continue to allow sales of glyphosate, which is used by thousands of British farmers to protect their crops and also by millions of gardeners to control weeds. The UK is expected to support renewing