If Cameron responds to Ukip defections by pandering to that party’s attitudes, the Tories will suffer for it in 2015

The battle between the Tories and Labour comes down to a single word: together. In his speech at the Labour Party conference Ed Miliband tried to make it his own by dint of simple repetition. At the Conservative Party conference which continues in Birmingham on Monday David Cameron, who has insisted for years that we are all in “this” – whatever “this” happens to be – together, the challenge will be to seize the word back.

Like most slogans that politicians hope will resonate around the country, it is at one level a platitudinous truism. The economic crash impacted on the vast majority of British people in one way or another. The deficit will hang round our necks and the necks of our children if it is not dealt with. Failure to stoke economic growth likewise will leave us all in trouble.

Achieving anything first requires digging us out of the deficit hole into which we tumbled in 2008, so Mr Miliband’s stroke of amnesia on the subject, failing even to mention it in his conference speech, was a solid-gold gift to the Prime Minister. Labour got us into this mess, and now it can’t even bear to talk about getting us out of it: that is likely to be the message.

For the Tories this is a rich seam. George Osborne has not, as he promised to do, eliminated the deficit in the course of one parliament, but his dour and relentless attention to bringing it down is finally getting results both in terms of economic improvement and public approval. Recent polls indicate that the Conservatives are more trusted with the economy than Labour.

Yet in other respects Mr Cameron’s claims on the “together” word are tenuous at best, and with the defection of a second Tory MP to Ukip they risk disappearing altogether.

If “together” means anything, it means a society which is concerned about the lot of the weakest and the poorest, which is committed to improving their long-term prospects while ensuring that they do not sink deeper into misery in the present. New research shows that such distressing post-crash phenomena as food banks, payday loans and fuel poverty have increased public awareness of poverty and empathy with those who are struggling to escape from it. There is also growing public awareness that, far from being the scroungers of tabloid and Benefits Street mythology, huge numbers of those drawing benefits are people in work who are forced to do so to augment their miserable earnings.

In keeping with his image as a one-nation Tory, Mr Cameron continues to pay lip service to the need to protect the poor, preserve and sustain the NHS and take meaningful action on the environment. But as his proposed cap on household benefits indicates, slashing it by £3,000 to £23,000, the audience he is really desperate to reach is the right wing of the party, increasingly tempted by the siren voices of Ukip.

In his last conference before the general election, Mr Cameron faces challenges enough to daunt any leader, including the new war in the Middle East and the promise to redesign our constitutional architecture at breakneck speed. There are the resentments accumulated among the party rank-and-file after years of collaboration with the Liberal Democrats. And now, with the defection of Mark Reckless to Ukip following that a month ago of Douglas Carswell, the danger of Nigel Farage’s party making deep incursions into Conservative support has never been more clear.

The question is how to respond to that threat. Does Mr Cameron have the will and determination to revert to the modernising course that gained him broad-based support at the last election? Or will he funk that challenge, quail before the Ukip menace and take his party haring off to the right? He may persuade himself that this is the only way to hold his party together. But if he believes that aping the anti-European, little Englander mentality of Ukip is the royal route back in to power, he is grossly deluded. It will be a one-way ticket to the wilderness.