ITV News' Political Editor Tom Bradby has tweeted:
My take on the debate so far; this format doesn't really suit Farage, who is shedding his cheery blokeish bonhommie.
He is coming across as a tad aggressive and didactic. Clegg is much the more experienced politician and it is showing.
Clegg is now quoting those stats from the OBR on how immigration is good for the public finances.