There has been in a trend over the past couple of decades of Parliament transferring legislative or quasi-legislative power to the government. My friend, the Liberal MP from Cambridge David Howarth, has written about this trend in a couple of recent op-eds: http://www.guardian.co.uk/commentisfree/2009/feb/04/house-commons-government-executive, and http://www.timesonline.co.uk/tol/comment/columnists/guest_contributors/article733022.ece