Calls are growing for Hungary's governing party, Fidesz, to be thrown out of the EPP.
Here's what it all means.
What is the EPP?
The EPP is the European People's Party, the biggest political family in Europe. It's an umbrella organisation for right wing, Christian democratic parties. Ten EU national leaders belong to the EPP and they control all three crucial EU institutions - the Parliament, the Commission and the Council.
What is the debate about?
Some members of the EPP want to remove Hungary's ruling party, Fidesz, because of the controversial positions of the Hungarian prime minister, Viktor Orbán. He is being criticized for his anti-immigration policies and accused of undermining democracy and silencing the media and more generally challenging EU values. EPP leaders fear that alliance with Orbán could harm their results at European Parliament elections this year.
The latest provocation from Orban's government was a billboard campaign attacking the European Commission's president Jean-Claude Juncker personally. Juncker is aligned with the EPP.
Why does Orbán want to stay in the EPP?
Orban recently said that Fidesz will not leave unless it is kicked out. Being in the most prestigious group is vital: he is in the club of decision makers such as Angela Merkel. The EPP has also successfully protected Orbán against EU sanctions.
Why is Fidesz important for the EPP?
Fidesz is by far the biggest party in Hungary with the support of around 50% of the population, winning all elections held during the last 8 years. They have 12 MEPs at the European Parliament. They might send even more after the elections this year, while the overall size of EPP is expected to fall. The EPP also says they can better control Orbán if he is inside the party.
What is the process for removing Fidesz?
Seven political parties from five different counties need to request the move. The EPP's political assembly has the final decision.
What would it mean if Fidesz would be excluded?
It would be a significant loss for Orbán. He could see the current EU action against Hungary speeding up without the shield of the EPP. Most likely Orbán would join Eurosceptics at the parliament and could be empowered to push further to the right extremes.
The EPP would lose its 3rd biggest party in the EU, and maybe Fidesz could bring some like-minded right-wingers with them. But it could also open up the way for a future coalition with leftist or liberals, like Emmanuel Macron's En Marche.