The wrangling over the vehicle duties is part of a raft of politically-charged trade disputes between the EU and Russia amid the Ukraine crisis.
At a meeting of the WTO's dispute settlement body, Russian diplomats excercised their right to oppose the creation of an independent panel of trade and legal experts to hear the dispute.
Under WTO regulations, Moscow can only do that once, leaving Brussels with the option of filing a second request at a later date.
The EU first launched its WTO challenge in May this year.
It objects to anti-dumping duties that Russia has slapped on so-called "light commercial vehicles" made by Germany and Italy, both of which are leading global players in the auto sector.
The 160 member economies of the WTO are allowed to impose extra duties when goods are being "dumped" on them – sold at below market prices to grab business.
But they must prove that their domestic producers are suffering as a result of dumping, and that they are not simply slapping on duties in order to hit foreign firms' trading position.
Moscow has rejected EU claims of any wrongdoing.
The EU, however, insists that the duties of nearly 30 percent are choking off the Russian market for such vehicles.
In 2012, the year Russia joined the WTO, EU exports of the vehicles to the country were worth more than €100 million ($127.5 million), according to Brussels.
The EU also charges that exports have been declining since Russia imposed a "recycling fee" on cars, trucks, buses and other vehicles, days after joining the WTO.
The WTO has already been called in to rule on an EU complaint over the recycling fees, which apply only to imported vehicles.
Brussels and Moscow are also sparring at the WTO over embargoes on a string of goods from ex-communist countries, several of which are now members of the 28-nation EU.
Since joining the WTO, Russia has imposed bans on dairy products, chocolates, wine and meat from countries including Lithuania, Poland, Moldova and Ukraine.
Moscow has cited quality concerns that allow countries to take such a step under WTO rules.
Critics say Russia offers little scientific evidence and that the bans are essentially a political swipe at countries that refuse to toe their Soviet-era master's line.
Russia, in turn, has hit the EU with a WTO complaint over Brussels' energy market reforms, which it says hurt its gas giant Gazprom.
The WTO polices global trade accords in an effort to offer its members a level playing field, and can authorise penalties against wrongdoers.