He calls this great vote swap plan "Country Before Party" but it would be more accurate to call it "Operation Save the Tories". He's on a hiding to nothing for a great many reasons.
Most UKIP voters aren't traditional Tory voters and most also say they wouldn't vote Tory even if there was no UKIP candidate. UKIP is taking council seats off the Tories, Labour and Lib Dems. We don't need the Tories to stand aside for us to win elections and it would be electoral suicide for us to help the Tories win elections when the majority of UKIP voters aren't traditional Tory voters and don't care whether Ed Miliband or David Cameron wins as long as they can do their bit to help UKIP take the fight to Westminster.
My own branch (Telford & Wrekin) has already said that we have no intentions of standing aside for Mark Pritchard MP, even if he talks like UKIPper to try and placate the rapidly dwindling membership in his constituency. After all, we're here to win elections for UKIP, not help the Tories. It would be great to have more branches (all of them preferably) pledge not to stand down for the Tories so Toby Young can stop wasting everyone's time with his pie in the sky plan to try and save David Cameron's skin and we can get on with winning the EU elections this year and shaking up Westminster next year.