Le Pen finds common cause with Europe's nationalists
More than a year after the European elections, a new right-wing nationalist group opposed to the EU has emerged in the European Parliament, led by Marine Le Pen and the French National Front (FN).
"The European Union is working to destroy the nation, and we are here to defend our people," Ms Le Pen told a news conference.
"Today, it's D-Day, it's the beginning of our liberation," said the Dutch MEP, Geert Wilders.
He added that the new group - which will be known as Europe of Nations and Freedom - would fight mass immigration and what he called the "Islamisation of Europe".
It has taken time to create the new bloc, which will now be eligible for substantial public funds. European parliamentary rules dictate that at least 25 MEPs from at least seven countries are needed to form a group.
One key addition was MEP Janice Atkinson, who was expelled from UKIP earlier this year.
She said Marine Le Pen and Margaret Thatcher were the two women she admired most in politics.
Ms Atkinson also said the suspension from the National Front of its former leader Jean-Marie Le Pen, Marine's father, had made it easier for her to join the new group.
But opponents said this was a dark day for the European Parliament.
Green MEP Jean Lambert described Europe of Nations and Freedom as a "monstrous mosaic" made up of MEPs who "want to divide society along racial, ethnic and faith lines".
Other parties joining the new group are Italy's Northern League, the Austrian Freedom Party, Flemish nationalists from Belgium's Vlaams Belang, and the Congress of the New Right from Poland.