televised TV voting only arrived in the polls in 2010 . Broadcasters are keen to adopt the head - to - head format in the run - up to the 2015 poll . But factional politics and uncertainty about who is invited may derail a TV debate .
Election TV debates only arrived in the UK in 2010 . Broadcasters are keen to repeat the head-to-head format in the run-up to the 2015 poll . But factional politics and arguments about who is invited may derail a TV debate .