The world's oldest insurance market is looking to leave its boozy past behind, as Lloyd's of London bans its staff from drinking between 9am and 5pm.

According to the Evening Standard, the 328-year-old market founded has told its 800 employees that they will be sacked for "gross misconduct" if they partake in alcohol during their working day.

The paper reports that some staff have reacted angrily to the ban, with one worker saying that it made Lloyd's "the PC capital of the world" and another asking: "Will we be asked to go to bed earlier soon?"

The internal memo reads:

"The London market historically had a reputation for daytime drinking but that has been changing and Lloyd’s has a duty to be a responsible employer, and provide a healthy working environment.

"A zero limit is therefore simpler, more consistent and in line with the modern, global and high performance culture that we want to embrace."

A Lloyd's spokesman told Reuters:

"It provides clarification on the rules around alcohol consumption, which is prohibited during business hours. The guidance removes any ambiguity on the policy... [And] ensures we are in line with a number of businesses in the sector who also adopt similar policies."

Brokers and underwriters who work for other firms at the HQ are not included.

The Lloyd's of London building. Picture by Stefan Rousseau PA Wire/PA Images

Liquid lunches are apparently still popular among some workers in the sector, with an insider telling the Financial Times:

"It still goes on more than you might expect. There is still a short hours and long lunch culture in some places and there are stories of brokers sitting in pubs handing out contracts like Jabba the Hutt."

With a high density of public houses located in London's financial district, publicans are likely to be affected by the ban, at a time when thousands of post-Brexit vote job losses in the City of London are already starting to hurt custom.

Indeed, Lloyd's is planning to move some of its operations out of London to a new EU subsidiary, with Dublin touted as one possible location.