Shares in Sports Direct International (SDI), the leading British sports retailer and wholesaler, jumped by nearly 8 percent in the week after the Conservatives' win in the British general election. Ed Milliband, Labour's candidate, has been outspoken about his disapproval of zero-hour contracts used by SDI and some other retailers, which bind employees without any guarantee of paid hours of work. SDI's chairman, Keith Hellawell, confirmed a few weeks ago that about 14,700 of the retailer's employees are on zero-hour contracts. The share price hike also came amid reports that SDI sold the lease for its offices of about 3,000 square meters on New Cavendish Street in London's West End for £44 million. SDI has reportedly instructed agents to find a site more than three times the size, to redevelop into a combination of offices, a Sports Direct store and a gym. Separately, SDI's head office in Shirebrook was visited by police earlier this month, but this was part of an investigation into the former ownership of the Rangers football club and not directed at Sports Direct or any of its employees or directors.