Police powers to stop and search: your rights
The police can stop and question you at any time - they can search you depending on the situation.
A police community support officer (PCSO) must be in uniform when they stop and question you. A police officer doesn’t always have to be in uniform but if they’re not wearing uniform they must show you their warrant card.
Being searched doesn’t mean you’re being arrested!
source: https://www.gov.uk/