Onward, described as an "ideas factory for centre-right thinkers and leaders", says the Tories can only be sure of victory in the next election if they double down on the levelling up which won it a host of Yorkshire seats from Labour.
But with the Conservatives currently lagging behind Labour in many opinion polls, it says Boris Johnson's party but must work to engage younger voters to maintain a majority coalition in the longer term.
According to the 'no turning back' report, one in five Conservative voters mostly concentrated in the so-called red wall of formerly-Labour held areas across the North and Midlands “lent their votes” to the Conservatives in December.
This trend, which saw the Conservatives win more votes than Labour across Yorkshire and the Humber, doubled the party’s majority from 42 to 80 but made it vulnerable if the party records a smaller vote share in 2024.
The report said Labour’s coalition is now ideologically split between moderate and hard left voters and could only ever win 37 per cent of voters or 260 seats in its current form. Keir Starmer must move to the right on both culture and economics to get anywhere near a majority, it said.
It argues that if the Conservatives can deliver on the 'levelling up' agenda aiming to boost the prospects of disadvantaged areas of the country they will consolidate their temporary coalition of provincial middle class and industrial working class voters and could make it permanent.
And it says it is a mistake to think the Conservatives are ideologically split between 'southern' conservatism on the one hand and 'Red Wall' conservatism on the other.
The Tories' old and new voters are united in wanting politicians to be tough on crime and immigration and to invest in and support communities and local economies.
Will Tanner, Director of Onward, said: “A year on from the election, it is fashionable to say Boris Johnson must choose between loyal voters in the South and new voters in the Red Wall.
"This is a false choice. The truth is that the party’s new coalition is not only more working class and provincial than before, it is more culturally coherent as a result."
Former Labour Don Valley MP Caroline Flint, who lost her seat to the Conservatives in December, said her party needed to “rebuild its relationship with those predominantly working class communities in the North who voted Tory”.
“Some people a year ago thought that the challenge for Labour, if there was a General Election, was losing middle class liberal voters,” she told The Yorkshire Post’s podcast, Pod’s Own Country.
But the “real challenge” was to keep the “working class base in the North who had for generations voted Labour, who went to the Tories”.
She said: "The Conservatives polled more votes in every social group in society, in the general election in 2019. That has never happened in my lifetime.
"And therefore the Labour Party has got to think about while being sensitive to liberal opinion, they have to have their ears open to be sensitive to our working class voters.
"There are similarities with the democrats in America, so it was interesting for me to see how Joe Biden was able to reach in and get votes back in states that were needed for him to become President Elect of the United States of America.
"That's where Labour has to be, it has to restore its trust with those communities."
She added: "In the Red Wall seats [...] I would have to say, and I was saying before, there was a reason why those voters went from us. And as much as anything, it was about a relationship that had been weakened, for a number of reasons.
"But that's where we need to make sure we don't think that that's just going to bounce back, we need to work hard to win their trust again. And I think Keir has made a good start."