Rishi Sunak and Liz Truss: Stakes high for first head-to-head debate

"One is the continuity candidate who stabbed Boris in the back. The other is the change candidate who stayed loyal."

A senior Conservative MP recounts the words of a local party member, when I ask why so many polls and surveys of Tory party members suggest Foreign Secretary Liz Truss is comfortably more popular than the former Chancellor Rishi Sunak, right now at least.

Neither camp dispute the handicapping in this race, before a vote has yet been cast. Such is the consistency of the evidence and the size of the current suggested gap between them.

This is the vital context as Liz Truss and Rishi Sunak head to Stoke-on-Trent, for a debate at 21.00 BST to be broadcast on BBC One and on Radio 5 Live.

To offer you a quick canter through it, there was this poll from YouGov, described by the pollster as offering "no good news for Rishi Sunak" when there were still four contenders in the race.

Then there was this one the other day when it was down to the final pair. It suggested a whopping lead for Liz Truss.

And surveys for the Conservative Home website have not made for comfortable reading for Rishi Sunak either.

In short, Liz Truss appears out in front. Rishi Sunak has lots of catching up to do.

And so this debate, and the ones to follow, really matter: The stakes are high and the cock-up potential is higher.

Yes, there are 12 hustings happening around the UK in the coming weeks but most Conservative Party members will not go to one, and plenty that do may already have made up their minds.

Yes, the candidates are hurtling around the place doing grip-and-grin photos with the grassroots to endear themselves to potential supporters. But plenty will not get to meet either, let alone both candidates.

Liz Truss is pictured here in Kent on Saturday meeting party members

And so the broadcast battle is vital.

"It is so important. Every party member will see the debate, hear reports about it, clips from it, or be left with some sense of who won it," one MP tells me.

But remember, the electorate to determine who wins is vanishingly small compared to the population at large.

The Conservatives will not tell us how many members they have, but we know they had 160,000 last time there was a leadership election three years ago, and it's thought they have roughly the same number now.

The population of the UK is about 67 million.

Which means less than a quarter of one per cent of the country gets a say in deciding who our next prime minister will be.

• Who are the Tories that will choose the next PM?

But the wider electorate do matter here too.

"The general public don't have a vote, but they do have a say," says an MP on Team Sunak.

What do they mean? Well, polling companies will ask after the debates which candidate is preferred by the wider electorate to be prime minister, and the results of those polls will have an influence on party members.

The hope on Team Sunak is this will be good news for them, and help turn the tide in this race.

They cling to the large number of undecided Conservative members, and hope persuading them and convincing others to switch might be enough.

Team Sunak are looking to the large number of undecided Conservative members

What inside track can I offer about the BBC debate?

Firstly we are in Stoke-on-Trent Central, because it is one of the many constituencies won by the Conservatives for the first time at the last general election in 2019.

A clear measure of the success or otherwise of Boris Johnson's successor will be whether they can hold on to those seats won when he was their leader.

Sophie Raworth is the presenter, there will be a studio audience and I'll join our economics editor Faisal Islam in offering analysis and some follow-up questions.

The studio audience will be made up entirely of people who voted Conservative at the last general election.

Some who did so for the first time, others who have done for longer. Some who remain loyal to the Conservatives and others who are wavering.

Again, if Liz Truss or Rishi Sunak are to win the next election, keeping people like those in our audience on side will be crucial.

As for the questions they'll be asked, well, that would be telling, wouldn't it? As well as your eyes flicking down this article - and thanks for reading - it may well attract the gaze of the campaign teams themselves.

Suffice to say, you can expect us to talk about the economy, given it's the biggest issue of our time and the two camps have been rowing about their different visions for it.

Boris Johnson, the very definition of the politics as performance politician

And the other thing these programmes tend to reveal, regardless of the subject matter, is a sense of the candidates' personalities.

Both will feel a deficit compared to Boris Johnson, the very definition of the politics as performance politician.

Perhaps any duo of potential successors would appear wooden in comparison. These two, at this stage at least, certainly do.

But the presentational styles of their campaigns are markedly different: Rishi Sunak is slick, Liz Truss pointedly isn't.

Being slick isn't necessarily a good thing.

So, it's the first full week of the contest proper, and probably the biggest audience for a TV debate between the two of them before ballot papers start arriving early next month.

"The Tory way is to vote early" one adviser says to me.

As one veteran of leadership races puts it, "it is a galling process, it is mind-numbingly exhausting and it has only just begun."

But it is also true to say all sides accept the next few weeks have an outsized importance.

And the debate in Stoke is a big part of that.

I can't wait.