The prime minister will struggle to get a better deal in Brussels if he is afraid to make a pro-European argument at home

The fact that European Union leaders and Britain’s prime minister say that relations should improve is no guarantee that they will. Overcoming structural obstacles to closer collaboration will require a consistent application of political will. Sir Keir Starmer’s visit to Brussels on Wednesday is a significant step in that direction. He held his first official bilateral meeting with the European Commission president, Ursula von der Leyen, as part of the “reset” that Labour promised in its election manifesto.

The prime minister has described his preferred relationship with European partners as “improved”, “ambitious”, “pragmatic” and “mature”. Any combination of those qualities would be welcome, but there is still some mystery surrounding the substance of what Sir Keir has in mind. The most concrete proposal, from the UK side, is a defence and security pact. This would go beyond military cooperation, encompassing energy supplies and combating the climate crisis. That makes sense from a strategic perspective and has the technical advantage of being feasible without amending the 2020 Brexit trade and cooperation agreement (TCA).