Since the election of Emmanuel Macron in France, the mood in Brussels has been positively giddy with the prospect of a “rebirth” of the European project, driven by the promise of the renewal of the ailing Franco-German partnership.

But the limits of the EU’s integrationist ambitions are being cruelly exposed by the fight between Poland’s hardline conservative government and the European Commission over whether Poland is failing to maintain the ‘rule of law’.

Europe has long been nursing a simmering east-west split over migration and fundamental values which this week has burst into open warfare. Here we look at how Poland’s constitutional crisis is threatening to pull Europe apart.

Briefly, what is the problem?

Poland is being accused of reneging on the commitment it made in 2004 on joining the EU to maintain “stable institutions guaranteeing democracy, the rule of law and human rights”.

The country’s ruling Law and Justice party, lead by the irascible and charismatic Jarosław Kaczyński, is accused by the European Commission of trying to push through reforms to the media and judiciary that are anti-democratic.