U.S. government to file antitrust lawsuit against Google on Tuesday - source

The U.S. Justice Department is expected to file an antitrust lawsuit against Alphabet Inc's Google on Tuesday for allegedly breaking the law in using its market power to fend off rivals, according to a source familiar with the planning.

The lawsuit is expected to allege that Google broke the law in how it treated rivals in its search and advertising businesses, seeking to disadvantage them to keep its own search engine dominant and using that market power to sell more ads.

Google did not immediately respond to a request for comment.

Coming just days before the U.S. presidential election, the filing's timing could be seen as a political gesture since it fulfills a promise made by President Donald Trump to his supporters to hold certain companies to account for allegedly stifling conservative voices.

The lawsuit comes more than a year after the Justice Department and Federal Trade Commission began antitrust investigations into four big tech companies: Amazon.com Inc , Apple Inc, Facebook Inc and Google. Groups of attorneys general also opened probes into Facebook and Google.