Image copyright LME

The days of long, booze-fuelled City lunches appear to be nearing an end as the London Metal Exchange becomes the latest firm to introduce a booze ban.

The exchange has said that all staff who work on its trading floor can no longer drink during working hours.

The ban affects about 120 personnel - from traders to clerks - of nine different firms who work in the Ring.

The move follows similar rules on alcohol and drugs from Lloyd's of London, introduced earlier this year.

"The LME appreciates the high standards upheld by its members, and has formalised the general position that Ring-based personnel should not consume any alcohol prior to conducting business," said a spokesperson.

The BBC understands that the decision is not related to any particular incident, but the exchange faced criticism earlier this year after one of its clients hosted a cocktail party at the Playboy club in Mayfair using LME branding.

In May, the exchange appointed its first ever female chairman Gay Huey.

The nine firms that work on the trading floor are currently in consultation with LME to decide how best to enforce the new regulations, which are not limited to the typical 9-5 working day.

'No ambiguity'

Ben Willmott, head of public policy at human resources trade body the CIPD, said it was common for firms to have a policy around how much alcohol was reasonable in working hours, even in industries which were not safety-critical.

"It makes sense to have a policy so that there is no ambiguity. A policy may well allow appropriate lunchtime drinking. It doesn't have to be a zero-tolerance policy."

Mr Willmott said having a policy on drinking made it easier for managers to raise the issue if there was a problem and to highlight the support available.