The British mapping company Streetmap wants to appeal against a High Court judgement that said Google goog did not break competition law by favoring its own maps in its results.

The judgement came through in February, in a long-running case that covered very similar ground to the EU’s antitrust investigations into the U.S. giant.

The judge, Mr Justice Roth, said Google’s 2007 introduction of its “OneBox” mapping service, at the top of location-related search results, was “not reasonably likely appreciably to affect competition in the market for online maps.”

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Streetmap, which was a decade old at the time but saw its traffic plummet when Google got serious about mapping, disagrees.

The company maintains that Google’s insertion of a proper map on its search results, while relegating rivals to less-useful blue links, was using its position to wipe out the competition. It has now asked the Court of Appeal to let it take the next step in its legal battle.

“The first instance judgement of the High Court gives the ‘giant’ a carte blanche to proceed without due consideration of its legal obligations,” the company said in a statement.

According to Streetmap, Roth made a mistake in the way he treated the concept of “abuse,” by looking for an “appreciable effect” from Google’s actions rather than a “likely” effect. Streetmap also thinks Google’s dominant position in the search market gives it special responsibilities towards other players, and that Roth misinterpreted evidence.

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The company is being supported in its fight by ICOMP, a lobbying group once backed by Microsoft that has a long history of bashing Google.

This may prove to be something of a return to form — last month ICOMP said it was backing away from the big EU-Google antitrust battle, prompting resignations from members who were outraged that the group was no longer being explicitly anti-Google.

“Google has a special responsibility as a dominant company to comply with the law and the burden of proof is on Google to show that it has complied,” ICOMP said in a statement. “It is surprising that the High Court thinks online competition will be protected from a dominant company’s abuse if online companies have to wait until the damage has been done to show they have been harmed.”

Google had not responded to a request for comment at the time of writing.

This article has been amended to note that Microsoft no longer backs ICOMP.