BNP leader Nick Griffin will not face any action after he published the address of a gay couple who won a landmark legal ruling on Twitter, police told the BBC.
The MEP published the address of Michael Black and John Morgan on the social networking site and called for a demonstration to be held outside their home.
Following a police investigation and advice from the Crown Prosecution Service no criminal offences were identified.
More top news
Weather set to stay cool and cloudy tomorrow
Europe's asylum, immigration and freedom of movement laws "wholly inadequate" to deal with arrival of hundreds of thousands of people.
A passenger who helped foil a suspected terror attack on a high-speed train in France is to appear on US show "Dancing With The Stars".