Ofcom is doing a consultation on 25MHz of spectrum in the 700MHz band, which is currently used by Digital Terrestrial TV. This has been talked about for a long time. The consultation closes on 20th May 2016 and Ofcom intends to publish a statement in Q3 2016. It seems likely that 4G or even 5G may be used on 700MHz.
http://www.ispreview.co.uk/index.php...broadband.html
http://www.ispreview.co.uk/index.php...broadband.html