Can foreigners be members in German parties and fully participate in them?

Question

The Bild recently argued against political participation by foreigners in the German party SPD. It seems that one doesn't need to be a German citizen to be a member of the SPD and take part in party activities such as voting.

I have two questions:

• Is this common among German parties, or is the SPD an outlier in this regard? (I was able to find the answer regarding memberships for the CDU (they allow it for Europeans with some restrictions) and Linke (they allow it), but not other parties like Grüne, FDP, AfD, etc).
• Do other parties restrict political participation of party members based on their nationality (eg they can be members, but not vote on (some) party matters)?

If it's not too broad, it would also be interesting how other European parties handle this issue.

Answer 1

There is one (minor) legal obstacle to allowing non-citizens joining a German political party: §2 part 3 of the Law on Political Parties (Parteiengesetz) states that a political group is not a party if:

• a majority of its members or of its leadership is foreign; or
• its seat or its place of business is outside of federal jurisdiction.

It seems highly unlikely for any of the current political parties in Germany to run afoul of these rules so until that becomes a danger there is no problem at all with non-citizens becoming members of political parties.

In general, the internal party rules will be codified in the Satzung. For example, the Satzung of the Greens is available for download from their website. As an example, it explicitly states that anybody can become a member of the Greens who agrees with their principles and rules and is not a member of any other party (§4(1)).

I disagree with your interpretation of the text on the CDU's page (or maybe that changed since 2018); as I read it, citizens of EU countries can become CDU members without restrictions while citizens of non-EU countries can become CDU members if they resided in Germany for at least one year.

Taking the generally accepted left-right political spectrum in Germany and recalling the general principles left and right-leaning parties tend to follow, I believe it is pretty safe to assume that if the CDU allows non-citizen membership all other large parties (except maybe the AfD) will do so too; without personally wanting to go through their individual websites.

Answer 2

In the UK, the two major parties are Labour and the Conservatives. The Labour party restricts membership to

...subjects/residents of The United Kingdom of Great Britain and Northern Ireland or citizens of Eire or other persons resident in The United Kingdom of Great Britain and Northern Ireland for more than one year... Labour Party Rule Book

The Conservative party has no such rule, except that

The Party is a political Party for the Nation, open to all who share its objects and values and who undertake to be bound by this Constitution. Constitution of the Conservative Party

It is common for parties to establish International organisations, such as International Labour or Conservatives Abroad to cater for foreign members and supporters.