In June paying for sex will become illegal in Northern Ireland. It will be following Sweden and Norway in criminalising men who use prostitutes. There are calls for the same to be done across the rest of the UK. Others argue that the best protection for prostitutes is actually legalisation. Catrin Nye has been looking at how the system works in the UK at the moment meeting current and former prostitutes, men who pay for sex and police. She travels to Sweden with campaigners who want their model adopted.