It was a day of huge symbolism on December 14, 2019, when hours after starting his new term as Prime Minister, Boris Johnson arrived in the County Durham constituency which for years had been the patch of Labour premier Tony Blair.

The Labour stronghold of Sedgefield was one of a swathe of 'red wall' seats - from Wakefield to Leigh and Bishop Auckland - where voters cast off decades of tradition to vote Conservative for the first time, ushering in an 80-seat majority for what seemed to be an invincible PM.

"I know that people may have been breaking the voting habits of generations to vote for us," Mr Johnson told Sedgefield Cricket Club. "And I want the people of the North-East to know that we, in the Conservative Party, and I will repay your trust."

Fast forward to July 2022 - three years almost exactly since the phrase 'levelling up' was coined - and the slogan used to sum up his plan to spread opportunity to left-behind parts of the country in the North and Midlands is starting to ring hollow.

The twin headwinds of the pandemic and the cost-of-living crisis - plus the constant whirr of scandal surrounding the PM himself - have understandably dominated his government's attention and left little bandwidth for the complicated task of undoing decades of worsening inequality.

But as two recent reports have set out all too clearly, in many parts of the North the dramatic events of the last two years have actually set the cause back even further.

In figures which shame any developed nation, child poverty rates in West Yorkshire have soared from from 28% in 2015 to 33% in 2021, despite falling in the South. And those figures mask an even grimmer picture in Bradford where the number of children classed as living in poverty is almost 50% in some areas.

And it doesn't stop there.

More than 50,000 homes will be classed as living with fuel poverty in the district this year, compared to 27,000 three years ago. In one inner-city Bradford constituency, a staggering 44.6 per cent of households were already living in fuel poverty even before record increases to the energy price cap.

It’s clear that after a pandemic which hit the North’s towns, villages and cities harder than those in the South East, the argument for taking strong, concerted action is more powerful than ever.

Mr Johnson has in the last two years named a key department after 'levelling up' and tasked one of his most able Ministers - Michael Gove - with delivering his agenda.

But while the Red Wall seats that voted blue at the last election have enjoyed some crumbs from the table, the policy on which so much was pinned for Bradford - a new main-line railway station - has been shunted into the sidings and looks as though it will never happen.

For the thousands of families still held back by non-existent transport and a lack of jobs and skills, with inflation chipping away at their living standards, the idea that their communities are being 'levelled up' must seem almost laughable.

So with Boris Johnson now on his way out and Michael Gove abruptly sacked it's all the more alarming to read multiple reports in the national press that the agenda could be junked by the next PM.

Though the two remaining hopefuls, Rishi Sunak and Liz Truss, have made many of the right noises about their commitment to the cause it's been far from a top priority in a debate largely focused on tax cuts and culture wars.

At the heart of the issue is a problem under the bonnet of the North’s economy. The average Northern worker - for a whole host of reasons - is 50% less productive than one in London, a gap that’s widened rapidly in recent years.

Depriving Bradford of a high speed railway station may cut costs in the short term but how much will it waste in squandered potential in the coming decades as talented youngsters are cut off from good jobs?

And new analysis by the IPPR North think-tank released today shows the gap in public spending between the North and the rest of the country has actually widened during the last three years.

While total public spending in the North was £16,223 per person in 2021, up 17% on 2019, the England average rose by 20% and the London average by 25% to £19,231.

But this is not simply a case of the North with its begging bowl out asking for more cash from the hard-pressed taxpayer.

Lancashire MP Jake Berry, who leads the Northern Research Group of Tory backbenchers, includes in his four asks of the next PM a ‘levelling up formula’ which would equalise government funding and ensure the North is not left behind.

But he also proposes changes that will rewire our unequal nation and give communities in the North the ability to succeed on their own terms, including a greater emphasis on vocational training with our region at the heart of it.

Some changes have already been made to the Green Book - the Treasury’s method of deciding where public money should be spent - but more reform is needed if towns and rural areas aren’t to be held back.

And above all central government must stop hoarding power and press the accelerator on devolution, giving elected mayors with strong local mandates the ability to take control of their post-16 education systems.

The North deserves to know where Rishi Sunak and Liz Truss - the two contenders to be our next Prime Minister - stand on these issues and whether they’re truly committed to the hard decisions necessary to end the status quo.

And ahead of the first regional leadership hustings in Leeds this week major news titles across our region today put the following five key questions to the two candidates:

l What will you do to make sure the commitments made to the North by your predecessors as Prime Minister are kept?

l The average worker in the North is 50% less productive than one in London, what will you do to address this widening gap?

l What will you do to address spiralling rates of child poverty in parts of Northern England?

l How far will you go to give Northern leaders control over education and skills, transport and health budgets currently held by Westminster, and will you give them more powers to raise or lower taxes to boost local economies?

l Will you retain a government department responsible for tackling regional inequalities with a Cabinet-level Minister for whom this is their main job?

We’ll publish the responses later this week. And with Labour making the case that they’re now the true party of levelling up we’ll be asking them to answer too.

Nigel Burton is editor of The Press