BRUSSELS (Reuters) - The European Union is due to relaunch its powerful executive arm under the new leadership of the German conservative Ursula von der Leyen from Dec. 1 but faces legal risks after Britain refused to name its representative for the European Commission.

FILE PHOTO: European flags flatter outside the EU commission headquarters in Brussels, Belgium, September 20, 2019. REUTERS/Francois Lenoir

This is what has happened and why it matters.

WHAT HAS HAPPENED

Von der Leyen is going into the final confirmation hearing for her new Commission in the European Parliament on Nov. 27. If she wins the vote, as expected, she will lead the Brussels-based Commission for five years from Dec. 1.

The Commission has wide-ranging powers that include proposing policies on everything from migration to climate change, policing member states’ budgets and negotiating global trade deals. It is normally comprised of one representative from each of the EU’s 28 member states.

However, Britain has refused to name a commissioner as it plans to finally leave the EU on Jan. 31, although that hinges on Prime Minister Boris Johnson’s Conservatives winning a parliamentary majority in a Dec. 12 election.

The EU has pushed Britain on the matter and even launched a legal case against it.

WHY IT MATTERS

The legal risk for the EU is that any and all decisions taken by the new Commission could be challenged in the courts.

While there may be few policy proposals before the new Brexit date of Jan. 31, the divorce has already been delayed three times from an original date last March amid bitter infighting in Britain over how and even whether to leave the EU.

Any further delay would risk making any new EU policies susceptible to legal challenges for a longer time.

The Commission also acts as the EU’s competition watchdog and any anti-trust or merger decisions it takes during that time could also end up in court on the grounds that the executive had been established on a flawed basis.

WHAT’S NEXT

Britain has until the end of Nov. 22 to reply to the outgoing Commission on the legal case - a so-called infringement procedure - initiated against it by Brussels.

However, few expect London to act now, given its own ‘purdah’ rules which say a government should not make international appointments - including for the EU - during an election campaign and before a new government is in place following an election.

Trying to hedge their bets, the other 27 EU member states are therefore preparing a decision that would stress the legality of forming the new Commission without Britain.

It will be discussed by national envoys to Brussels at 1400 GMT on Friday and is due to be approved by EU development ministers meeting in Brussels on Monday.

Eventually, it would be up to the courts to decide whether any lawsuits are valid.