The Cost of Living in Sin. Three million Britons currently cohabit yet have scant legal protection, compared to married couples, if things go wrong. Sarah Spiller assesses the cost of being an unmarried couple and uncovers the political intrigue behind new Government proposals for cohabitees. Producer Fiona Gough : Editor Mike Robinson Repeated with sign language on Wednesday at 3.15am www.bbc.co.uk/panorama NOTE: as Panorama is likely to react to news. its subject matter may change RT SHOP: book, Panorama: 50 Years of Pride and Paranoia by Richard Lindley , is available from the RT Shop, price £17.99 inc p&p. Call [number removed] (national rate) orvisitwww.radiotimes.com/rtshop