Left wing demonstrators took to the German city of Koblenz today as populists from across Europe gathered at a conference.

Political parties, trade unions and even religious groups backed the demonstration, which saw people from Germany’s main establishment parties stand side-by-side.

Spiegel Online says the regional president of the state of Rhineland-Palatinate, Malu Dreyer addressed the crowd, saying the demonstration was “for freedom, for cohesion in our country, for metropolitanism and tolerance”.

German Vice Chancellor, Economy and Energy Minister Sigmar Gabriel (C) and his social democratic SPD party’s secretary general Katarina Barley (L) take part in the demonstration (Sascha Schuermann/Getty Images)

Police estimate some 3,000 protesters gathered under the banner “Koblenz is still colourful”, blocking one of several access roads to the conference hall but without disturbing proceedings.

Die Presse even reported that Luxembourg Foreign Minister Jean Asselborn would be among the protesters.

“We can not leave the fate of this continent to the nationalists,” he said, adding: “It is necessary to work for a Europe of the 21st century and not for a Europe of the 19th century.”

The conference was attended by French Front National leader and presidential candidate Marine Le Pen, German AfD leader Frauke Petry and Dutch populist Geert Wilders.

Also in attendance was Harald Vilimsky, leader of the Austrian Freedom Party in the European Parliament and Italian Lega Nord leader Matteo Salvini.

Some Germany mainstream media outlets were denied credentials for the conference, including broadcasters ARD and ZDF.

“The freedom of the press includes not serving the rights of fake news,” said co-organiser Marcus Pretzell.

The title of the conference is “2017: Year of the Patriots”.

“Koblenz is colourful” (Sascha Schuermann/Getty Images)

“Never again” (R), “they are back” (L) and “never fascism again” (C) (PATRIK STOLLARZ/AFP/Getty Images)

“Koblenz stays colourful” (PATRIK STOLLARZ/AFP/Getty Images)

“Koblenz stays colorful” (L) and “the fox is clever and plays stupid, with Nazis it is the other way round” (PATRIK STOLLARZ/AFP/Getty Images)

(PATRIK STOLLARZ/AFP/Getty Images)

(PATRIK STOLLARZ/AFP/Getty Images)

(PATRIK STOLLARZ/AFP/Getty Images)

(Sascha Schuermann/Getty Images)

The sign reads “Who is sleeping in a democracy could wake up in a dictatorship” (PATRIK STOLLARZ/AFP/Getty Images)

Left wing group Avaaz installed 10 ft high images of (L-R) Franco, Mussolini, Hitler, Stalin and Pétain. (PATRIK STOLLARZ/AFP/Getty Images)