The future of UKIP
9 December 2012 Last updated at 21:32 GMT
How worried should the Conservatives be about UKIP? Nigel Farage's party, which wants Britain out of the European Union, is on a roll after finishing second in two recent by-elections and getting its best ever share of the vote in a parliamentary seat. Although polls show UKIP has been winning over voters from all three main parties, some Conservatives feel they've most to lose. Leala Padmanabhan has been to a marginal constituency in Lincolnshire where the Tory MP is feeling the heat from UKIP.
This report was broadcast on Sunday 9th December on BBC Radio 4's The Westminster Hour.