The results of the general election were devastating for Labour. Devastating for my friends and colleagues who lost their seats – and for their staff who lost their jobs just before Christmas. But more than anything, it was devastating for millions of people in our country who desperately need a Labour government. We let them down, and for that we are truly sorry.

Turning this result around, winning back the seats we lost and winning additional ones needed for a majority requires a careful analysis of the reasons for our defeat and a sober reflection on how our movement should respond.

In 2017 we won 3.5 million extra votes, making huge strides in winning back the 5 million votes lost between 1997 and 2010 after backing war and proposing austerity.

But something significant obviously changed between 2017 and last week. Given that we had the same leader in Jeremy Corbyn and a similar manifesto to 2017, I think it is mistaken to focus blame there.

Of course, Jeremy came up on the doorstep. But this is the fourth Leader I’ve campaigned for and each time – whether it was Tony Blair and Iraq, Gordon Brown, Ed Miliband or Jeremy – the Leader always came up.

Nobody campaigned with greater energy, resilience and principle than Jeremy and all of us in the Shadow Cabinet need to accept responsibility. We can’t allow blame for this election to fall on Jeremy’s shoulders alone, just as we all accepted the praise when, in 2017, we secured the highest increase in our vote since the Second World War.

My experience on the doorstep, in my strongly Leave constituency, suggests this defeat was because this became the ‘Brexit Election’ that Boris Johnson wanted. That triumphed over traditional party allegiances.

By that I don’t just mean that people wanted to get beyond Brexit – and who can blame them when it’s been a black hole sucking the life out of all other issues that need tackling in our communities, such as poverty pay, crumbing schools, boarded up high streets or a broken social care sector?

But Brexit also became an issue of trust. The failure to “get it done” meant many people simply did not believe we’d be able to deliver on our ambitious manifesto. Put simply, the mood was: if you won’t honour the referendum, then why should we trust your pledge to deliver a huge house building programme, a £10 per hour minimum wage or scrap tuition fees?

Regaining that trust is the first step towards winning. Initial assessments of YouGov, Ashcroft and Datapraxis data suggest Labour lost, more or less, the same numbers of votes to both Remain and Leave parties.

In rebuilding, Labour must be the champion of the whole working-class: whether in towns and cities, whether Remain or Leave, and ensure we are a party that reflects the diversity of the working-class in 21st century multicultural Britain. Nostalgia has no role to play in making Labour successful again.

But any realistic assessment must acknowledge that over 50 of the 60 seats lost were in Leave areas. When campaigning in many constituencies across the North and Midlands, as I did, I heard people say they were ‘lending’ their vote to the Conservatives.

We certainly can’t take it for granted that those voters, or Labour voters who stayed at home, will back us next time. Scotland shows what can happen when people break with their pattern of voting for Labour.

So, whoever becomes Labour’s next Leader must establish a Special Commission looking into those lost Leave seats. In many of them, our support has been declining for a number of years before it passed the tipping point this year.

While this was a Brexit election, the next one won’t be. Labour now needs to prepare itself to fight the next war, not the last one. That means having answers to the big challenges our communities face.

How do we get wages to recover to pre-crash levels? What will be the basis of a growing economy outside of London and the South East? How do we restore skilled, secure jobs to areas that haven’t had them in decades? How do we properly fund public services? How do we ensure everyone has a decent place to live? How we do fight widening inequality and discrimination? How do we tackle the climate emergency quickly enough?

Labour’s recent manifestos were widely praised and offer solutions to many of these big questions. For example, it would be wrong – for people and planet – to abandon the plans for a Green Industrial Revolution and rest our hopes on market-driven economics.

Our version of the Green New Deal would help unite our voters in small towns and big cities by both tackling the climate emergency and creating much-needed manufacturing jobs in our communities hit hard, first by deindustrialisation and then by austerity.

But we cannot be complacent and assume having the correct policies is enough. The election underscored a lack of public trust, and so we need to work on making our policies resonate better with communities.

Personally, I think Labour should now focus-in on ten of our key manifesto policies and use these as the basis of our campaigning and dialogue with voters over the next five years.

It would give us a set of policies that we can easily communicate as a vision of hope against the cruelty that will come from the Johnson government. And it would be a campaigning tool for members to go out into their communities and show, day after day, that Labour is on their side.

We can then use every media opportunity we get, every parliamentary debate, every public meeting, and every campaign day to register this alternative with the public ahead of the next election.

Others may think that we need to triangulate instead. The evidence does not support this. A weakening of Labour’s popular commitments to ending austerity, returning rail, mail and water to public ownership and a more interventionist role for the state would not win more votes.

Take a look across Europe, where once great parties of State such as the French Socialist Party and German Social Democrats abandoned their base and now find themselves at historically low levels of support – securing just 6.4% in France at the last presidential election.

Change is going to be needed, but we need to ensure we don’t throw the baby out with the bathwater. In a parliamentary system we will rightly always be judged by the number of seats we have won.

But in rebuilding for the future we also have to recognise that this year with 10.3 million votes we got 750,000 more votes than Blair’s winning total in 2005 (9.6m) and a higher share of the vote and greater number of votes than in both 2010 (8.6m) and 2015 (9.4m).

This is not an attempt to gloss over the scale of defeat – we all care too much about the communities we represent to do that – but to acknowledge that answers cannot be easily found in simply looking to the past.

Instead in the coming Leader and Deputy Leader elections we need an open debate in which all wings of the Labour movement set out how they can rise to the challenges posed by Thatcherism 2.0, and how as socialists we can again earn people’s trust and support.