For many progressives, 2016 will go down as a year of electoral shocks and profound disappointment.

In the US, France and many other parts of Europe, the right enters 2017 with newfound confidence while the left recoils in fear of the future, unsure how to get back on the front foot.

Today’s report from the Fabian Society shows that Britain is far from immune from this, and highlights the scale of the task Labour faces across Britain if we are to win back public confidence and power. This is a time of huge change and huge challenges for progressive politics.

But 2017 cannot be the year of lamenting our losses; it must be the year we turn the tide and set out a bold, ambitious vision that can rebuild and reunite Britain. A key part of that, of course, will be shaped by the Brexit negotiations.

As I set out in a recent speech at Bloomberg, Labour will be at the heart of the fight for a better Brexit deal – one that puts jobs, the economy and living standards first, and argues for a more cooperative, collaborative future relationship with the EU: one that ensures Britain remains outward-looking and preserves our ability to trade in goods and services with a market of 500 million people.

We will fight against a hard Brexit and the damage that would do to our economy

Above all, we will fight against a hard Brexit and the damage that would do to our economy and communities across the country. We will also oppose the divisive rhetoric of the right and seek to bring the country together around a Brexit deal that is in the national interest.

The nature of the final Brexit deal really matters. It is, as I have said before, the battle of our times.

Labour will provide effective opposition to hard Brexit in parliament and ensure there is the scrutiny, rigour and accountability that Theresa May is so keen to avoid.

Ensuring we have the best possible Brexit deal will take time, effort and huge diplomatic skill. It also requires the prime minister to go against her form and be more open, accountable and willing to answer tough questions.

So the resignation today of Ivan Rogers as the UK’s permanent representative to the EU – a highly respected figure in Brussels and Westminster – is a worrying sign. Rogers was right to emphasise the likely complexity of striking a final Brexit deal within two years, and the prime minister needs to be far more willing to hear difficult truths. Having recently met Rogers to discuss the Brexit process, I am in no doubt his early resignation will be a real loss.

But while the immediate focus of the Brexit debate is on process and personalities, this cannot be the full story.

If Labour is to reconnect with voters across the country and rise to the challenge of Brexit, we need to ensure that the process of exiting the EU is one part of a more comprehensive, ambitious response. We need also to comprehend and analyse the underlying social and economic causes of the referendum vote and offer a positive, progressive vision that addresses these.

Among the issues our response to Brexit must tackle are: worsening economic exclusion and widening economic inequality; the absence of an effective industrial strategy to rebuild communities and provide higher-paid jobs; lack of public faith in the immigration system; a chronic skills gap that holds back too many people; and a profoundly worrying lack of public trust in a political system that concentrates power away from communities.

In truth, these issues have been ignored for far too long. Even if the referendum result had been a narrow win for remain (ie 52%-48%), they would still need to be addressed. In light of the Brexit vote, Labour now has an urgent obligation to do so.

We can of course be certain that Conservatives and the right of British politics have no answers to these profound challenges. Indeed, every indication is that Theresa May’s government will make these problems worse and leave Britain even more divided than it currently is.

The good news for Labour is that the answers to these challenges lie in our values – solidarity, equality and social justice. Our profound and enduring commitment to human rights and internationalism will also underpin and shape Labour’s vision of Britain in the world.

The bad news is that crafting these answers, and a bold project for the future, will not be easy. Indeed, this is a generational task.

But, as with the best moments in our past – 1945, 1964 and 1997 – Labour should not be frozen in the face of huge challenges, but inspired to find bold, progressive solutions. That is the task the left and Labour in particular must turn to in 2017.