Millions of people across England, Scotland and Wales are set to vote in the largest set of polls since the general election in 2024.
Voters in Scotland and Wales will choose who should run their national parliaments, while seats on dozens of councils and mayors are up for election in England.
The polls will be open between 07:00 BST and 22:00 BST on Thursday 7 May, with results expected to follow on Friday and over the weekend.
The polls will be the biggest test of public opinion since Labour won the general election in 2024.
These will be the second set of elections during the premiership of Prime Minister Keir Starmer.
