Twenty-three job-hunting sites have written to the EU’s Competition Commissioner to ask Google to withdraw its first-party job listing tool from its search results, Reuters reports. The sites, which include UK site Best Jobs Online and German sites Intermedia and Jobindex, claim that Google is unfairly pushing users toward its own service, while their pages are being pushed down in search results. There are also fears that, in the future, Google may start running ads on the search tool, and the search giant could eventually cut these third-party job listing sites out entirely.

Google’s tool appears if you search for terms relating to common job roles like “call center jobs.” Although it links out to various job listing sites where you can actually submit an application, the tool includes features of its own like the ability to save listings, filter results, and set up alerts.

Other job listing sites are seeing an increase in traffic

The complaint comes just over two years after Google was fined a record-breaking €2.4 billion (around $2.6 billion) for manipulating search results to prioritize its own shopping comparison service. Although there are similarities between the two complaints, the difference here is that the job listing sites aren’t being cut out of the process entirely. Google still links to them for you to actually apply for the jobs, and it doesn’t offer its own application process. However, these 23 firms argue that linking to competing services doesn’t amount to “equal treatment.”

In a statement provided to Reuters, Google says that the current tool, which was launched two years ago, was designed to address these previous antitrust complaints. It added that it prominently links to job listing sites. One of Google’s senior product managers for Google search, Nick Zakrasek, says that many job listing companies “have seen a significant increase in the number of job applications they receive,” and that “by improving the search experience for jobs, [Google is] able to deliver more traffic to sites across the web and support a healthy job search ecosystem.”

Not every job listing site objects to the tool. Some have welcomed its introduction, which Reuters reports drew 120 million clicks in June in the US. One job listing provider, iCIMS, says that the tool is now the third-largest source of referrals to its clients’ pages, and its applicants are more likely to be hired. In order to benefit from this traffic, sites have to format their listings in a way that Google’s algorithms can easily read. One such site, Monster, has been asking its customers to do just that in an attempt to recover customers lost through poor search engine rankings for its regular pages.

If the EU decides to open a formal investigation, it could be one for its new Competition Commissioner. The current commissioner, Margrethe Vestager, is due to leave the position at the end of October, although Reuters notes that she is expected to prepare an “intensive” handover to her successor.