A decade on from the referendum, it is clear that the decision to leave the European Union has both harmed our country’s economic prospects and our international influence.

Estimates of the economic hit range from 2 to 8 per cent of GDP. The Office for Budget Responsibility reckons on a 4 per cent loss compared with staying inside the EU.

Politically and diplomatically, Britain chose to leave the EU just as the Russian threat to the security of democratic Europe increased and the United States became a less reliable and more self-interestedly transactional ally.

It’s little wonder that even the strongest champions of Brexit try to avoid talking about it, and that roughly 60 per cent of voters now think that it was a mistake.

The challenge now, for both London and Brussels, is how to establish a constructive working relationship to deter threats to our security and prosperity and advance the many interests that the UK and the EU have in common.

For now, incremental improvements, with a new partnership on defence and civil resilience as the top priority, offer the best way forward.

There is little appetite in the EU for bolder moves, especially given the political turbulence at Westminster. The reality is that for EU leaders the Union’s relationship with Britain is a long way from the top of their list of priorities.

In the longer term, rejoining may be possible. It will depend on how the European Union develops (next year’s French presidential election is only one of the uncertainties about the EU’s future) and on the terms of membership available. Politically, a further referendum in the UK would be unavoidable to confirm the legitimacy of a decision to reverse the electorate’s decision in 2016.

It takes time for political bruises to heal and trust to be rebuilt. But despite the challenges ahead, I remain optimistic about forging a renewed, close partnership between our country and the rest of democratic Europe. The change in public opinion since 2016 provides an opportunity: the shifts in geopolitics make it essential to our national interest that we succeed.