In 2008, electrification was ruled out on grounds of cost and difficulty of electrifying a line with so many viaducts and bridges,<ref name="1541/2008"></ref> but the Network Route Utilisation Strategy published by Network Rail in October 2009 showed a benefit–cost ratio for the scheme of 2.4:1.<ref name="1158/2012"></ref> In 2012, the Mayor of London, Boris Johnson, indicated that funding was "a matter for the Department for Transport".