Some journalists might be barred from covering the meeting of European right-wing populist and and anti-immigration party.
The Alterative for Germany (AfD) plans to meet France's far-right chief Marine Le Pen, Dutch anti-Islam lawmaker Geert Wilders and Italy's Matteo Salvini of the Northern League on January 21 in the western city of Koblenz.
The AfD's Marcus Pretzell, a co-organiser of the conference for some 1,000 delegates, announced that all publicly funded media would be barred, reported German news agency DPA.
Reporters from German news weekly Der Spiegel, the daily Frankfurter Allgemeine Zeitung, business newspaper Handelsblatt and the magazine Compact had also been denied accreditation, said Pretzell, a regional party leader.
Pretzell charged in comments to DPA that public broadcasters were biased against them and could produce their "scripted" stories without having access to the conference.
While the banned journalists would not be able to cover speeches by AfD leader Frauke Petry, Le Pen, Wilders and others, all would be able to attend press conferences, he said.
Chief editors of German public broadcaster ARD accused organisers of the meeting of "massive interference in media freedom" and said they may take legal action.
German Journalists' Association chairman Frank Ueberall said political parties that shape public life have an obligation to allow open press coverage.
The AfD, which opposes Chancellor Angela Merkel's liberal refugee policy, has enjoyed a surge in support in a series of state elections over the past year.
Ahead of general elections likely to be held in September, the party is polling at around 15 percent.