“It’s like the straitjacket has come off.”

So said the BBC’s Emily Maitlis after Boris Johnson’s victory speech on the steps of Downing Street on Friday afternoon, during which the PM celebrated an “overwhelming mandate” from the general election to deliver Brexit.

Reading between the lines, there was a clear message in his speech – accept Brexit is going to happen.

But there was also something else – a sense of unity as he declared a “one nation” Conservative government would allow the UK to “find closure and to let the healing begin”.

He welcomed voters in constituencies that had turned blue overnight, adding: “I’m proud to say that members of our new one nation government, a people’s government, will set out from constituencies that have never returned a Conservative MP for 100 years.”

Johnson then appealed to Remainers, insisting his “one nation” government would never ignore their feelings of “warmth and sympathy” towards the other nations of Europe.

“I frankly urge everyone on either side of what are, after three and a half years, increasingly arid argument[s] – I urge everyone to find closure and to let the healing begin.”

So this “one nation conservatism” sounds quite nice, but what actually is it?

The term dates back to the philosophy of Britain’s first Jewish prime minister, the Conservative Benjamin Disraeli, who in the 1845 novel Sybil examined the gap between the wealthy elites and the working classes.

Disraeli surmised that Britain was “two nations; between whom there is no intercourse and no sympathy; who are as ignorant of each other’s habits, thoughts and feelings, as if they were dwellers in different zones, or inhabitants of different planets.”

Although Disraeli never used the term himself, his work as PM to bridge the divide through paternalistic policies that encouraged the wealthy to assist the less well off has since become known as the original example of one-nation conservatism.

Back in 2010 when he was mayor of London, Johnson detailed his own interpretation of the philosophy whilst talking about the need to keep the capital a “competitive, dynamic place to come to work”.

But how does this same philosophy apply now he is PM with a huge parliamentary majority?

Johnson’s comments reflect an appreciation of the truly tectonic shifts in the country that last night meant seats that had been Labour for nearly a century ditched Jeremy Corbyn and flocked to the Tories.

Some of the starkest defeats for Labour came in the north of the UK, traditionally working class areas and some ex-mining communities that have never elected a Tory.

Johnson spoke directly to these voters when he said: “In this moment of national resolution I want to speak directly to those who made it possible, and to those who voted for us for the first time and those whose pencils may have wavered over the ballot and who heard the voices of their parents and grandparents whispering anxiously in their ears.

“I say: thank you for the trust you have placed in us and in me.

“We will work around the clock to repay your trust and to deliver on your priorities with a parliament that works for you.”

One nation conservatism is the most convenient catch-all term to appeal to both traditional Tory voters and the party’s new converts.

But to keep the converts converted, Johnson will have to address the issues that – outside of Brexit – are typically of concern in these areas, and which voters traditionally look to Labour to look after.

The most obvious of these is the NHS.

The PM addressed this in his victory speech, saying: ”I’ve heard it loud and clear from every corner of the country that the overwhelming priority of the British people now is that we should focus above all on the NHS.”

He added: “That simple and beautiful idea that represents the best of our country with the biggest ever cash boost, 50,000 more nurses, 40 new hospitals as well as providing better schools, safer streets and in the next few weeks and months we will be bringing forward proposals to transform this country with better infrastructure, better education, better technology.”

The biggest test for how committed to one nation conservatism Johnson actually is will be if he delivers on his promise to “repay” new Tory voters in working class areas.

He has not got off to the best start – that promise of “50,000 more nurses, 40 new hospitals” was already proven to be hollow during the campaign.

There is also has another facet to the “one nation” rhetoric – one incredibly advantageous to the PM.

By invoking terms like “one nation” and “the people’s government” – which, given the whopping majority he secured last night he can legitimately now do – he can now ignore any talk of second referendums or anything else that could potentially get in his way of delivering Brexit.