Angela Rayner MP is backing the campaign against lifting the ban on bee harming pesticides.
She has added her name to the growing list of MPs of all parties who are opposed to lifting the ban.
Neonicotinoids have been restricted across Europe since 2013 due to mounting evidence that they pose a risk to bees.
Bees are responsible for pollinating two thirds of the food we eat.
But the National Farmers Union (NFU) has applied to the government to lift the ban in some parts of the country. Ministers are currently considering their application.
Angela took the pledge to oppose the lifting of the ban at a Parliamentary event held this week, organised by 38 Degrees and Friends of the Earth.
MPs heard new evidence from scientists and from a Lincolnshire farmer who had stopped using these pesticides before the ban.
Speaking after the event, she said: “My postbag has been full of pleas from local people to oppose this move.
“I have listened to their concerns and I’ll be making my opposition very clear in parliament to any plan to lift the ban.
“Bees are essential for pollinating our crops – we can’t afford to gamble with their future. The Government must keep these dangerous pesticides out of our fields.”