WASHINGTON (Reuters) - The U.S. government will layout its antitrust case against Alphabet's Google in closing arguments on Thursday, wrapping up a trial in which the online search leader is accused of breaking the law to stay on top.

The U.S. government has hammered away at Google in a trial that started Sept. 12, arguing Google is a monopolist and illegally abused its power to favor its bottom line.

This case, filed by the Trump administration, was the first of five aimed at reining in the market power of tech leaders. The second, against Meta, was also filed during the Trump administration, while Biden's antitrust enforcers have followed with a second case against Google and cases against Amazon.com ( AMZN ) and Apple Inc. ( AAPL )

In the non-jury trial, the judge will weigh whether Google violated the law, and will later look at any punishment if needed.

Witnesses from Verizon, Android maker Samsung Electronics ( SSNLF ) and Google itself testified about the company's annual payments - $26.3 billion in 2021 - to ensure that its search is the default on smartphones and browsers, and to keep its dominant market share.

In his testimony, Google CEO Sundar Pichai acknowledged the importance of making its search engine the default on phones, tables and laptops to keep users loyal, saying: "We definitely see value."

In turn Google has argued the government was wrong to allege it broke the law to hold onto its massive market share, saying its search engine was wildly popular because of its quality and that dissatisfied users can easily switch.

Furthermore, despite Google's multibillion-dollar payments and Pichai's statement, Google's lawyers have argued that being the default has limited value and that users will not stick around if they are unhappy.