Election event

My client owns two houses one in London and one in the country. They were both bought in 2003 and neither has ever been let. There is no doubt that his main residence for the purposes of TCGA 1992 s 222 was the London property until recently. However he married on 1 May 2007 and his wife now occupies the country house full-time while he uses the London property five days a week and spends weekends at the country house. He is planning to sell the London property in two years' time and would like to treat the country house as the main residence for capital gains tax purposes from the date of marriage onwards. He is of course out of time to make an election (see s 222 (5)) but he would like to create an opportunity to make an election....