The Lord Chief Justice, the Master of the Rolls and the President of the Queen's Bench Division will begin hearing an appeal today by three former MPs and a peer who deny fiddling their expenses. The defendants are challenging a ruling earlier this month by Mr Justice Saunders that the defence of parliamentary privilege does not preclude their trial in the Crown Court. I explain the background to today's appeal in my column for the latest print edition of Standpoint, which has just been published.