Nigel Farage led his fellow Ukip MEPs in an act of protest against the European Parliament as they turned their backs while the European Union's anthem played.
The Ukip MEPs' show of defiance took place as a chamber orchestra opened the parliament's first session, which saw German socialist Martin Schulz elected president, by playing Beethoven's Ode to Joy.
Although most MEPs stood up for it, British Tory MEPs sat quietly while Ukip MEPs turned their backs on the orchestra and the EU flag.
Other newly-elected Ukip politicians took part too, like Janice Atkinson and Steven Woolfe.
Ukip turns back on opening of Parliament to anthem. Don't recognise flag nor anthem pic.twitter.com/JDAeKzMzMT— Janice Atkinson MEP (@JaniceUKIP) July 1, 2014
Woolfe said that the show of protest was against the "done deal' for Schulz's election as president of the EU parliament, adding: "Only the Labour group in the EU and their Socialist partners clapping Shultz in his speech for EU Parliament president."
Schulz got 409 votes in the 751-seat chamber, after his Socialist S&D bloc backed the conservative ex-Luxembourg premier Jean-Claude Juncker to be European Commission president.
Tory MEP Sajjad Karim, a rival candidate for president of the European parliament, condemned a "cosy consensus brokered behind closed doors", and said that the job of president had been "reduced to nothing more than a bargaining chip".
UKIP deputy leader Paul Nuttall MEP explained: "We don't recognise or respect the EU flag or anthem. They are both symbols of our servitude inside a political union which the British people reject.
"We will do everything we can in European Parliament to oppose the Federalist system which ignores our national democracy and pushes millions of people across Europe into poverty and unemployment. We stand up for our people, not the EU flag and anthem.
"National democracy and EU membership are incompatible. We will do everything we can to free ourselves from this corrupt institution."
However, Liberal Democrat MEP Catherine Bearder criticised the Ukip politicians for their "shocking disrespect" during the opening ceremony, describing their actions as "rude'.