The shortlisted proposals for the next fourth plinth commissions are unveiled in London. Artists Marcus Coates, Hans Haacke, Mark Leckey, Liliane Lijn, David Shrigley and Ugo Rondinone have created maquettes of their proposed designs. The two selected artists will be announced in early 2014, and their works unveiled in Trafalgar Square in 2015 and 2016 respectively