David Cameron used a sex joke to attack Jeremy Corbyn over his economic credibility in an attempt to paint the Conservatives as the party of financial security. The prime minister, speaking at the Tory conference in Manchester on 7 October, made the quip about tax campaigner and so-called Corbynomics architect Richard Murphy.

"He's the Labour Party's new economics guru and the man behind their plan to print more money," Cameron said. "He admitted that Labour's plan would cause a 'sterling crisis', but to be fair he did add, and I quote, that it 'would pass very quickly'. Well, that's alright then. His book is actually called The Joy Of Tax. I've read it. It's got 64 positions – and they're all wrong."

Cameron also joked about lurid allegations made against him in Lord Ashcroft's Call Me Dave book. The prime minister explained that he was a "hooker" when he played rugby at Eton. "That is a factual statement, not a chapter in Michael Ashcroft's book," Cameron added.

But the light-hearted remarks were accompanied by a serious theme, as the Tory leader repeatedly emphasised the issue of security. During the keynote speech, Cameron said the Conservatives would seek to "save Britain from the danger of Labour" and "rebuild Britain so it is greater still".

The address was one of the prime minister's most major speeches since surprising pollsters and securing a majority in the House of Commons. Cameron had revealed to the BBC during the election campaign that he would not stand for a third term, a commitment the Conservative leader referred to during the address.

"As you know, I am not going to fight another election as your leader. So I don't have the luxury of unlimited time," he said. "Let me tell you: I am in just as much of a hurry as five years ago. Securing our country, growing our economy; jobs, exports, growth, infrastructure: these are the stepping stones on the path to greatness for our country – and we've been laying them every day since we came to office. We will continue to do so."

'Deep social problems'

However, Cameron said he would draw on the tradition of "Conservative social reform" and attempt to tackle the UK's "deep social problems". He said: "The scourge of poverty. The brick wall of blocked opportunity. The shadow of extremism – hanging over every single one of us."

"A Greater Britain doesn't just need a stronger economy – it needs a stronger society. And delivering this social reform is entirely fitting with the great history of the Conservative Party who have always been the optimists, the agents of hope and the leaders of change.

"Now, in my final term as prime minister, I say: let's live up to the greatest traditions of Conservative social reform. It becomes clearer by the day that the Labour Party has completely abandoned any notion of these ideas."

Elsewhere, the prime minister announced his administration would build 200,000 "affordable" houses by 2020, when the next general election will be held and Cameron will step down as Conservative leader.

The 48-year-old said he wanted to transform "Generation Rent" to "Generation Buy" by pushing for developers to offer "starter" properties for first-time buyers under the age of 40. "When a generation of hard-working men and women in their twenties and thirties are waking up each morning in their childhood bedrooms – that should be a wake-up call for us. We need a national crusade to get homes built," he said.

But Labour claimed Cameron and his party were not meeting expectations while in power. "The Tories are failing working people. For all the talk of making life better for people, the truth is David Cameron is doing the opposite," said Jonathan Ashworth, a shadow minister without portfolio.

"You can't claim to care about the housing crisis when you've overseen the lowest level of housebuilding in peacetime since the 1920s. And you can't claim you care about the NHS when you've pushed up waiting lists, made it harder to see a GP and plunged hospitals in to financial crisis."

Richard Murphy had not responded to a request for comment from IBTimes UK at the time of publication.