The European Court of Human Rights has upheld a union's decision to expel a British National Party (BNP) activist.
The train drivers' union Aslef threw out Jay Lee, from Bexley, London, as he was an active member of the party.
This was challenged in the courts, but the European Court ruled unions can expel BNP members without breaching the European Convention on Human Rights.
A spokesman for the BNP said it was another example of the "establishment stopping its members".
In 2002, Mr Lee won an Employment Tribunal about the expulsion, but the decision was overturned on appeal in 2004.
Trade Union Congress (TUC) general secretary Brendan Barber described the European Courts ruling as an "important and welcome judgment".
He added: "The European Court has made the common sense decision that the right to freedom of association does not force unions to accept into membership people opposed to the basic principles of trade unionism.
"Every union will welcome this clear decision that they can now expel BNP members."
Andy Reed, national officer of Aslef, said: "This is a significant decision not only for us but for the whole trade union movement."
A spokesman for the BNP said: "We are further hardened in our resolve following this ruling.
"We are a nationalist party and the trade union leaders are antithesis to this - they are internationalists."