Prime Minister reveals Benny Hill hit is the only song he can sing in full . Stopped short of bursting into song but recited first verse to prove it . Comment: Watchdogs have received hundreds of complaints of bias against Miliband .
Prime Minister reveals Benny Hill hit is the only song he can sing in full . Stopped short of bursting into song but recited first verse to prove it . Bizarre moment came while cameras were off during TV election contest . Watchdogs have received hundreds of complaints of bias against Miliband .