UKIP threat to Tories: Mark Field and Douglas Carswell
A Conservative MP said some Tory voters think "UKIP speaks more for them than the coalition government" on issues such as immigration, grammar schools and law.
And Mark Field said there was little doubt that UKIP would do very well in the 2014 European elections, while a referendum - set to be offered by David Cameron on Friday - would be "something in the long grass past 2015".
Fellow Conservative MP Douglas Carswell said UKIP gaining between 10% and 20% in the polls would be an "existential threat to the careers of a lot of colleagues".
They debated the threat from UKIP to their party, along with YouGov pollster Stephan Shakespeare after watching a Daily Politics film.
- BBC News