The April 16 vote is on on shifting to a presidential system, which critics fear will concentrate too many powers in the hands of President Recep Tayyip Erdogan.
Prime Minister Binali Yildirim has already campaigned for a "yes" vote in Germany and said Erdogan also would address Turkish citizens in Europe.
In a response to criticism from Austria, Deputy Prime Minister Numan Kurtulmus said after a Cabinet meeting that the Turkish leaders would not be interfering in elections in that country.