Martin Hemingway, Green Party candidate in the European elections 2009, commented: "The UK Government has been trying to keep the opt-out in despite the UK having some of the longest working hours in Europe.
"This is not good for people's health and it limits the time workers can spend with their family and friends. This legislation will protect workers' health and safety by limiting the average working week to 48 hours over a 12 month period."
The UK opt-out could now be phased out within three years.
Mr Hemingway added: "Working time rules are designed first and foremost to protect the health and safety. There are many serious health issues related to our long-hours culture including stress, anxiety and depression, as well as cardiovascular disease, diabetes and insomnia. This vote now gives UK workers the right to enjoy a healthier work-life balance."
Jean Lambert, Green MEP for London and Member of the Employment and Social Affairs Committee, has been heavily involved in negotiations on the Directive.
She said: "Most long hours employees are not paid for their overtime and therefore have little to fear in terms of their earnings if we end the opt-out. Unsurprisingly, seven out of ten people who work unpaid overtime want to cut their hours. Over half of those doing paid overtime also want to reduce their working time.
"The UK Government has been pressurising MEPs to vote to keep the opt-out, thereby leaving UK workers open to exploitation. Workers here should not be expected to work longer hours and have fewer rights than those on the continent."