Earlier, Farage revealed he would be willing to let MPs stand on a joint Ukip-Tory ticket, estimating that about "a couple of dozen" may be willing to do this.
At least 11 prospective Tory candidates, an estimated seven of whom have a reasonable chance of winning their seats, have been delegates or speakers at training conferences run by the Young Britons Foundationn, which claims to have trained 2,500 Conservative party activists.
Owen Paterson, the environment secretary, led an unofficial rebellion by an estimated 136 Tory MPs in rejecting Cameron's plea.
It also estimated 12 Tory marginals could be ripe for the taking by either Labour or the Liberal Democrats if enough under-25s voted.
Mr Cameron needs to win over a number of Labour MPs to outweigh an estimated dozen Tory MPs who are still opposed to air strikes in Syria.
The result meant the prime minister, who won the support of an estimated 127 Tory MPs, including one teller, failed to win more than half of his 303 MPs.
I'm dressed in a suit so I must be 'Tory scum': pic.twitter.com/Yji2OCHuWA Early estimates suggested around 80,000 people attended the event, which featured speeches by people including musicians Charlotte Church and Billy Bragg, and writer Owen Jones.
The Tory-led Local Government Association estimated the elections would cost £50m – the cost of 700 police officers.
He should have said that, as the Home Office has estimated, the proposed Tory cap would only cover 20% of migration to the UK and accused Cameron of putting forward an empty immigration promise.
The prime minister would need the support of about 30 Labour MPs to have a chance of forcing her deal through, assuming she managed to also sign up the Democratic Unionist party, to offset the estimated two dozen Tory diehards who will never support the prime minister.
