The hard-drinking culture of the money-broking industry was laid bare in London's High Court.

Steven Horkulak, formerly a senior managing director at Cantor Fitzgerald, the US-owned inter-broker, detailed his "excessive" drinking and cocaine abuse and explained how his work regularly involved socialising with clients until the early hours.

He told the court that poaching staff from rivals was "top of the list" of his responsibilities.

He said members of staff would be entertaining banking clients every night of the week and he would always be invited, often attending two or three functions a night. "We were obliged to go out with a client and sit with him until he was ready to go home," he said. "If I got up and left some people might take offence at that."

Mr Justice Newman, hearing the case, said: "I don't entirely understand why it's so stressful going out and meeting people and drinking with them. Some people would think it was a wonderful way to spend the day."

Mr Horkulak, who now earns £300,000 plus bonuses at Tullet, another trading firm, told the court that the pressure of holding on to clients was stressful. He added: "I was in an environment where there was a lot expected of me, a lot of hours. I had to keep going. And how I chose to keep going was through the excessive use of alcohol and drugs."

He said he would commonly drink eight bottles of lager and 10 shots of vodka in an evening and take up to four grammes of cocaine a week. But he had stopped drinking heavily and had not taken cocaine from October 1999 until the beginning of 2001 - seven months after he left Cantor in a state close to a breakdown.

Details of the Cantor "culture" were revealed last year when the company clashed with rival Icap in an "employee poaching" trial. That case included evidence of "whoring parties".

Mr Horkulak, 39 and married with three children, was head of global interest rate derivatives. He is suing for constructive dismissal. He claims Lee Amaitis, Cantor's international president, treated him "like dirt" and hysterically screamed obscenities at him over the six months before he left.