comres for itv , which staged the debate , had cameron , miliband and farage tied first with 21 % and sturgeon close behind on 20 % .
icm for the guardian scored it miliband 25 , cameron 24 , farage 19 and sturgeon 17 .
yougov for the times put sturgeon first with 28 points to 20 for farage , 18 for cameron and only 15 for miliband .