Why, when anyone mentions they are on tv on the Jeremy Kyle Show, do they say "national tv"? And not just tv??

Guaranteed every single episode someone will say it!!!

Because the phrase stems from US talk shows like "The Ricki Lake Show", and in the US there is a difference between "television" and "national television". Because the US is such a large country, there are many local and regional television channels which produce a portion of their own programming, so any shows which are produced by these channels are not "national televion".

But yes, there's no need for the use of that phrase in England!

Sounds better.....

in case they mistakenly thought they were on international tv, or maybe local tv, even worse on the radio?
You have seen how stupid people are on there, it's no wonder really they have to be reminded where they are!

Because there are lots of different regions like when the news comes on after the main news you get the regional news ie; Scotland today, Northwest tonight, London news etc.

to make it sound better, have you also noticed the people who go on it are peasants, who seem to be shameless in airing their dirty laundry.