Video: PM on ‘Labour’s clear threat to security of British families’

“Frankly the risk there is today can be summed up in one word, security,” he said during a speech in Leeds.

“People desperately want in our country economic security so their families can get on, national security so our country can be safe.

“I think that frankly all the candidates for the Labour leadership demonstrate the same problem, which is they will not deliver the economic security that we need because they won’t deal with the deficit - some of them are in favour of printing money Zimbabwe style - they won’t deliver the national security we need at a time of trouble whether we are dealing with terrorism or Russian expansionism in Europe or other problems in our world.”

The Prime Minister said he had watched the contest to succeed Ed Miliband with “bewilderment” and argued that, whoever wins on Saturday, Labour is now an extreme party that “no longer represents working people”.

In a signal of his intention to seize some of the political centre ground previously staked out by New Labour, Mr Cameron framed the Conservatives as the “progressive” party that is seeking to spread opportunity for all and increase social mobility.

And he said that the Tory Government will pursue these goals by following the example of successful businesses, seeking new ways of doing things and delivering more for less in what he terms “a smarter state”.

Listen: Cameron in off-camera ‘jibe’ at Yorkshire