There is great concern across Europe about the collapse of bee populations.
Neonicotinoid chemicals in pesticides are believed to harm bees and the European Commission says they should be restricted to crops not attractive to bees and other pollinators.
But many farmers and crop experts argue that there is insufficient data.
Fifteen countries voted in favor of a ban – not enough to form a qualified majority. According to EU rules the Commission will now impose a two-year restriction on neonicotinoids – and the UK cannot opt out.
The Commission says it wants the moratorium to begin no later than July 1 this year.
The UK did not support a ban – it argues that the science behind the proposal is inconclusive. It was among eight countries that voted against, while four abstained.