Warsaw - Warsaw and Brussels may have put on a united front over the Belarus migrant crisis, but analysts doubt the cooperation will extend to their longstanding row over judicial independence.

For years now the European Union has viewed Poland as a problem child because of controversial judicial reforms that Brussels believes undermine the rule of law but which Poland says will root out corruption among judges.

The confrontation escalated last month after Poland's Constitutional Court challenged the primacy of EU law. Europe's top court ordered Warsaw to pay one million euros a day for not suspending a "disciplinary chamber" at the heart of the feud.

That standoff now appears to have taken a backseat as the bloc works to tackle the migrant wave on the Belarusian border with Poland.

Thousands of migrants, mainly from the Middle East, are camped out on the border in what the West says is a crisis engineered by Belarus to divide the EU and hit back against sanctions, charges Minsk has denied.

"The crisis has certainly resulted in some sympathy from the EU for Poland. The government was supported by the Commission and most member states expressed solidarity with Poland," political expert Marcin Zaborowski told AFP.

"European public opinion also is largely with Warsaw on this issue, not least because of the rise in anti-immigration sentiment," said the policy director at the Globsec think tank.

While the urgency of securing the border has overshadowed the rule of law conflict, observers say all signs point against any chance of Brussels letting bygones be bygones.

"There is no connection between demonstrating understanding for Warsaw's position in this border conflict and other issues that continue to poison Poland's relations with the EU," Zaborowski said.

"Warsaw's conflict with the European Court of Justice and the Commission over the rule of law remains unresolved and there is no indication of any backing down on behalf of EU institutions."

- 'No leniency' -

The European Commission continues to hold back approval of 36 billion euros ($41 billion) Poland wants from EU coronavirus recovery funds because of Warsaw's perceived roll-back of democratic norms.

The heads of the European Parliament's main political groupings addressed a joint letter this week to Commission chief Ursula von der Leyen urging that the money stay blocked until Poland yields.

On Thursday and Friday, EU Justice Commissioner Didier Reynders is due in Warsaw to hold talks on the conflict.

"There won't be any leniency here for the government just because the border issue arose," political scientist Stanislaw Mocek told AFP.

"The European Union does not want to set a precedent regarding Poland in which the country will be somehow rewarded for unlawful activity," said Mocek, head of Warsaw's Collegium Civitas University.

"On the other hand, we also have a threat to the EU border and on that matter there is overriding agreement that we must defend the border. So these are two separate issues."

He added that when it comes to the judicial conflict he does not see Poland backing down either, since on the border issue too, Warsaw has shown it wants to handle it in its own way.

"The Polish government has signalled that it wants to handle it on its own, and not with some pronounced assistance from EU countries or the European Commission," Mocek said.

"So there's some reservation here too, which is why I think there won't be any softer approach to the earlier issues, such as the fines."

By Anna Maria Jakubek