The man walked into the shop at around 11.15am, threatened staff and made off with a quantity of cash, said Sussex Police. No one was hurt, the force confirmed.

Police said the assailant made no attempt to disguise himself. He is described as white, mid-50s, 5ft 8in tall of slim build with short brown hair.

Detective Inspector Catherine O’Connor said: "This brazen man walked into the travel agent on a very busy street in the centre of Brighton, did you see anything?

“Although he hadn’t covered his face, did you see a man leaving the area in a hurry at 11.20am?"

A Tui spokesperson added: "We are aware of an incident that occurred at our Brighton store and are assisting the police with their investigation.

"The safety of our customers and colleagues is of paramount importance and can confirm that everyone in the store was safe.

"We have made the decision to temporarily close the store and will provide further updates in due course."

Anyone with information is asked to call Sussex Police on 101 quoting serial 349 or 22/10 or pass any information anonymously to Crimestoppers on 0800 555 111.