Sir Nick's Job For Life

I thought that only union bosses, dictators and royalty were granted jobs for life; but, according to The Independent (title link), Sir Nick Serota is one of the chosen few. Here's the lad himself, wondering whether to buy a pair of Tracey Emin's knickers for Tate Modern: Sir Nicholas Serota Makes an Acquisitions Decision (2006) courtesy of Charles Thomson of Stuckism fame (CLICK). The Tate Board decided to pre-empt the Prime Minister's decision on whether Sir Nick should be reappointed as Tate Director. I mean who takes any notice of that loser now that he's betrayed the Brit. working class and the Labour Party and his days at No 10 are numbered? However, the loser recently appointed Elisabeth Murdoch as a Tate Trustee for four years from 18 August 2008 (CLICK). So how come the Tate Board is claiming ignorance of the law when it comes to Sir Nick? Scared of losing him to the Russians?