Voters are being sent postal ballots with a guide that strongly suggests they should vote to for Britain to remain in the European Union, prompting furious complaints from anti-EU campaigners.

Voters in Bristol who have registered to vote by post have received a “how to vote by post” form as part of their voting packs which were sent out at the end of last week.

The step by step guide includes advice to “read the instructions carefully, then complete your ballot paper” above an image showing a pencil in a hand ticking a box to “remain a member of the European Union”.