Tory MP Stewart Jackson: UKIP threat to Conservatives
2 July 2012 Last updated at 12:22 BST
UKIP leader Nigel Farage claimed David Cameron delivered the "most pro-EU speech he has ever given", days ahead of a Daily Telegraph article appearing to offer the British people a referendum on Europe.
Conservative MP Stewart Jackson, who resigned as a ministerial aide after he voted in favour of a referendum, said he agreed with Nigel Farage that UKIP was "a major threat to the Conservative Party at the general election" and could deprive his party of an overall majority at the next general election.
They were debating the UK role in Europe as former Defence Secretry Liam Fox claimed the UK should leave the EU unless there is a rebalancing of the relationship.