The European Commission is pushing Google to have more transparency in its display of flight and hotel prices.
Google has been given two months to communicate changes to its Google Flights and Google Hotels searches.
Alongside Consumer Protection Cooperation authorities, the EC is asking Google to comply with EU law, saying "consumers need to know how the results of their search … are ranked and if payments may influence the ranking."
In a statement, the EC said flights and hotels presented on Google should be "final and include fees or taxes that can reasonably be calculated in advance."
Didier Reynders, European commissioner for justice, said: "EU consumers cannot be misled when using search engines to plan their holidays. We need to empower consumers to make their choices based on transparent and unbiased information."
The statement adds that if changes made by Google don't go far enough, a "follow-up dialogue will take place. National authorities may ultimately decide to impose sanctions."
A Google spokesperson said, "We welcome this dialogue and are working closely with consumer-protection agencies and the European Commission to see how we can make improvements that will be good for our users and provide even more transparency."
The search giant has had ongoing challenges from European regulators over search rankings and its dominant position for many years.
In late November, legal representatives from travel companies including Awaze, Booking.com, eDreams Odigeo and Expedia wrote to Margrethe Vestager, commissioner for competition, asking the EC to enforce its dominance decision from 2017 when the search giant was fined 2.42 billion euros.
At the time, and despite proposals around the regulation of digital gatekeepers, signatories requested immediate action.
Google is also under pressure from U.S. regulators with the Justice Department filing an antitrust suit against the company in October 2020.