With effect from 6th April 2014, it is no longer possible for employers to reclaim statutory sick pay from the government. See this statutory instrument.
Previously, employers could reclaim any amount of SSP which exceeded 13% of its national insurance contributions in the month. The rationale for abolishing it is that it gave employers an incentive not to encourage long-term sick employees to return to the workplace.
The money saved (estimated at £50m a year) will be put towards the new Health & Work Service, due to start in 2015, which will help employees and employers put together plans to facilitate a return to work. Here's a really good article on the new Health & Work Service.