Britain is blocking attempts to introduce a Europe-wide ban on the world's most widely used insecticides, neonicotinoids, arguing their impact on bees is unclear. British MPs say the government is acting complacently.

"We believe that the weight of scientific evidence now warrants precautionary action, so we are calling for a moratorium on pesticides linked to bee decline to be introduced by 1 January next year," said Joan Walley, chair of the committee.

The European Commission has proposed neonicotinoid sprays be restricted to crops not attractive to pollinators.

Two-thirds of wild species such as honey bees, considered vital for pollinating around one-third of the world's crop production, have suffered population declines in Britain, the parliamentary committee said.