But Syngenta, which makes the systemic insecticide Thiamethoxam, is unhappy at the committee's approach. Head of public affairs Luke Gibbs told Grower it had been established to consider a single variable - the action of insecticides on pollinating insects - when the problem of pollinator decline is "multi-variable", he said.
"They will only look at a narrow range of scientific papers. But the real threats to bees are the Varroa mite and habitat loss. Focusing only on pesticides could lead to recommendations that are not balanced."
Gibbs added that the inquiry "has inevitably attracted groups that are ideologically opposed to pesticide use", and he noted: "Several of the committee, such as Caroline Lucas, Zac Goldsmith and Martin Caton, have a long-stated public position on this."
NFU horticulture adviser and lead on bee health issues Chris Hartfield also gave evidence at a committee session the previous week. "We accept the precautionary principle," he said. "It is embedded within EU law.
"We do not think it is appropriate for it to be brought to bear in this particular circumstance because we do not see that there is a compelling weight of evidence demonstrating that neonicotinoids are responsible for the widespread decline in pollinator populations."
He argued that the precautionary principle aims to enhance environmental protection. "In this circumstance, that cannot be demonstrated because of the high risk that the alternatives to neonicotinoids - that would be used if neonicotinoids were banned - would pose to bees, to other pollinating insects and indeed to all beneficial insects."
The committee has also taken oral evidence from the Pesticides Action Network, the UK Pesticides Campaign, Buglife, the Soil Association, and academics in the field. It is expected to make its recommendations by the end of next week, with Defra then stating in January whether or not it intends to abide by those recommendations.
"Neonicotinoids were first used in agriculture in the mid 1990s and this was exactly the time when mass bee disappearances started occurring. The evidence against these chemicals is strong enough that they have been banned or suspended in France, Germany and Italy - but not yet in the UK. The Government must follow the lead of other European countries, which have taken steps to ban neonicotinoid pesticides."
Peter Melchett, Policy Director, Soil Association.