Spouse

includes-(a) a single woman who has lived and cohabited with a single man as if she were in law his wife for a period of not less than five years immediately preceding the date of his death;and (b) a single man who has lived and cohabited with a single woman as if he were in law her husband for a period of not less than five years immediately preceding the date of her death- The Pensions (Superannuation Funds and Retirement Schemes) Act 2006