The study, which polled 500 intermediate managers in London, reveals 21% use drugs due to peer pressure in the work place. Worryingly, 21% also reveal they take them in order to conform with their boss, possibly in the hopes of being promoted.
Other reasons cited for taking illegal drugs at work are that the drugs encourage creativity (12%) and help manage the stress of the job (10%).
Of those consuming drugs at work, a vast majority (90%) are choosing 'class A' drugs, with two fifths (40%) taking cocaine. A fifth (20%) of those taking drugs in the workplace admit to taking MDMA and Ecstasy, whilst nearly a tenth (8%) are choosing dangerous party drug GHB.
Sophie Hobson, editor of Londonlovesbusiness, said: "These results are startling. Although there is a general awareness that drug use goes on in the work place, the research highlights just how prevalent this issue is in London businesses, which is particularly worrying with the Christmas party season just around the corner.
"Tory MP Louise Mensch recently admitted to taking drugs whilst working for EMI and according to the research, clearly she's not the only one."
Drug deaths are three times the average in the EU, having risen to 49 out of every one million people in 2006 to 59 out of every 1million in 2009, according to figures from the EU drug agency.