Turkey is holding a crucial referendum on April 16 when voters will decide whether to approve constitutional changes that would create an executive presidency, boosting the powers of President Recep Tayyip Erdogan.
The huge Turkish diaspora in Europe is a key constituency for the Erdogan government.
In Germany alone, there are some 1.4 million Turks who can vote in the referendum, making them the fourth largest voting bloc after Turkey's three biggest cities. There are also huge Turkish populations in the Netherlands and Austria.
Turkey has been dispatching ministers to various European cities to drum up support at rallies, but many of them were blocked from doing so.
One reason is that many European governments have expressed disquiet at Turkey's response to a coup attempt against Mr Erdogan last July and a perceived slide towards authoritarianism, the BBC reported. Tens of thousands of public officials were arrested or sacked from their jobs.
Earlier this month, the German authorities in Gaggenau, in Baden-Wurttemberg, revoked permission for Turkish Justice Minister Bekir Bozdag to address a rally. A few days later, officials in Cologne did the same for Economy Minister Nihat Zeybekci. Both cited security concerns as the reason for the decision. Hamburg officials also banned a rally featuring Foreign Minister Mevlut Cavusoglu.
The Netherlands, where there are nearly 250,000 eligible Turk voters, last week also cited security concerns when it barred Mr Cavusoglu from entering to address a rally in Rotterdam. It also expelled Family Minister Fatma Betul Sayan Kaya.
Austrian Chancellor Christian Kern said on Monday that his country will also prevent visiting Turkish ministers from campaigning, on the grounds of public safety and because they promote "abolishing democracy".
President Erdogan has described the bans as "Nazi-style" practices, comments that have drawn widespread condemnation. Turkish government- controlled papers suggested that Germany was targeting Mr Erdogan's party while allowing Turkish opposition politicians to hold political meetings.
Turkey retaliated against the Dutch ban by suspending high-level relations and cancelling permission for all Dutch diplomatic flights to Turkey.
BLOOMBERG, AGENCE FRANCE-PRESSE