Austria is taking the German government to the European Court of Justice (ECJ) over its controversial road toll bill, the Austrian transport minister announced on Thursday.

The controversy over Germany's highway toll plans has gone on for several years, with Austria having long threatened to take legal action against a bill which they believe contravenes EU law as it specifically disadvantages foreign drivers using German roads.

After years of legal wrangling over the bill — which was rejected by the European Commission as recently as 2015 over the aforementioned issues — alterations were made in 2016 and it was finally passed by the German parliament earlier this year.

Originally proposed in 2013, the law was expected to come into effect in 2019 but Austria's decision to pursue the matter in Europe's highest court may delay, or indeed torpedo, the entire process.

The announcement by transport minister Jörg Leichtfried, a member of the social-democratic SPÖ party, comes in the final days of what has been a fiercely contested Austrian election campaign. The Austrian legislative election takes place this Sunday, with Leichtfried's party expected to suffer losses.

"This is indirect discrimination on the basis of nationality," Leichtfried said on Thursday. "This is about creating a (European Union) where the strength of the law counts and not the law of the stronger one," he added, referring to Germany's dominant position within Europe.

Leichtfried said the Austrian government will present its 30-page lawsuit to the ECJ later on Thursday, and expects the case to come before the court either in late 2018 or early 2019.

All are equal, some more equal than others?

Austria has long since been opposed to the bill, along with several of Germany's border neighbours such as the Netherlands and Belgium. "I consider this toll discriminatory and not reconcilable with EU law," Leichtfried said after the bill was approved in March. "We know now that Germany has agreed a foreigner toll."

The toll was originally branded by the German CSU party in 2013 as "a toll for foreign travellers on German highways", but after major objections, it has been heavily revised and rebranded since.

Read more: Don't get too upset about tolls on the German autobahn

At the heart of the controversy over the bill is the fact that drivers resident in other countries driving on German roads would ultimately have to pay more than German citizens for using the roads. While tolls would apply to all road users, German drivers would be able to recover much of the costs through tax deductions and other reductions based on the size and environmental standards of the car.

An interesting battle lies ahead; although the revised law was approved by the German parliament and seemingly set to become law, a legal assessment commissioned at the behest of the German Green party in February concluded that despite the changes, the bill was indeed discriminatory under EU law that guarantees equal rights for EU citizens.

aos (Reuters, dpa)