EU Commissioner for Traffic Siim Kallas had told the Deutsche Verkehrs-Zeitung it was completely wrong that he would support the proposals for such a toll, which has been suggested by German Transport Minister Alexander Dobrindt.
"We will be observing with great attention if there is any discrimination in the German system," Kallas underlined. "We will never accept" a one-sided charging of foreigners, he added.
Bures said on Monday all experts would regard German plans as a breach of the principle of equal treatment. "We will make use of all resources available to ensure there is no discrimination of Austrian drivers," Bures emphasised.
The German plan from 2015 is to impose a motorway tax of about €100 annually on everyone. However, German drivers themselves will be able to reclaim the highway toll as a tax write-off.
Austria, which has its own motorway tolls, valid for everyone including Austrians and Germans, was amongst the first to complain about the German plans.
Up until now, there has been no toll at all on German motorways, which are among the most heavily frequented in Europe.