Dan Hannan MEP on Tory defectors Carswell and Reckless

The combined Tory and UKIP polling amounted to nearly half the electorate, but the split was set to see Ed Miliband elected as prime minister with 35% of support, said a Tory Eurosceptic.

Dan Hannan, an MEP for the South East of England, said he would not be joining his friends Douglas Carswell and Mark Reckless, who are standing down as Tory MPs to fight for their current seats as UKIP candidates.

Asked by Andrew Neil on the Daily Politics for a guarantee that he would not be defecting, Mr Hannan answered: "Yes".

The MEP said David Cameron's referendum pledge had "changed everything", but added it would a "tragedy" if UKIP split the vote and prevented a Tory majority, which allowed in Labour and the Lib Dems.

BBC coverage of the Tory conference on Monday

BBC index: Party conferences 2014