Google CEO Sundar Pichai is set to tackle President Donald Trump's accusations of political bias head-on.

On Tuesday, Pichai is scheduled to be grilled by the House Judiciary Committee — his first time being questioned by Congress since he became CEO in 2015.

"I lead this company without political bias and work to ensure that our products continue to operate that way," he will say, according to prepared remarks.

One expert told Business Insider that there was "zero" evidence to support the theory that Google was fixing search results against Republicans.

Google CEO Sundar Pichai plans to send a message to US President Donald Trump during his grilling by Congress on Tuesday.

In prepared remarks published ahead of his House Judiciary Committee hearing, Pichai tackles the issue of political bias head-on, following several attacks from Trump and other prominent Republicans.

The president said in August that Google's search results were "RIGGED" against him, while last month he asked his Twitter followers to "check out how biased Facebook, Google and Twitter are in favor of the Democrats."

Read more: This graph shows 90% of political donations from big-tech workers went to the Democrats, with Googlers leading the charge

House Majority Leader Kevin McCarthy and Rep. Jim Jordan of Ohio are also among those to have accused Google of punishing conservative voices in search results.

"I lead this company without political bias and work to ensure that our products continue to operate that way," Pichai plans to say in response to the claims. "To do otherwise would go against our core principles and our business interests."

He will add: "Users also look to us to provide accurate, trusted information. We work hard to ensure the integrity of our products, and we've put a number of checks and balances in place to ensure they continue to live up to our standards."

You can read Pichai's full remarks here.

He is expected to face tough questions about search results, potential antitrust issues, and Google's plans to launch a censored search engine in China. His testimony is scheduled for 10 a.m. ET (7 a.m. PT) on Tuesday. It will be Pichai's first time being questioned by Congress since he became Google's boss in 2015.

Ari Ezra Waldman, the director of the Innovation Center for Law and Technology at the New York Law School, said there was "zero" evidence to support the theory that Google was fixing search results against Republicans.

"Republican rhetoric around anti-conservative bias is merely a pretext, part of the current administration's undemocratic assault on the free press," he told Business Insider. "It's part of a larger narrative that conservatives are under attack. It fuels the conservative base to lash out.

"What comes up on search results on Google, for example, is the product of Google's highly complex and proprietary algorithm, which is sensitive to what other people click on, share, and so forth."

Still, Business Insider revealed recently that employees at Google's parent company, Alphabet, had donated far more money to Democrats than any of their peers at the other so-called FAANG companies (Facebook, Apple, Amazon, Netflix, and Google) since 2004.

Employees donated $16.3 million to the party, which was nearly $10 million more than employees from the next biggest funder, Amazon, according to the figures from GovPredict. Overall, 90% of the $40 million donated by big-tech employees to political causes since 2004 has gone to the Democrats.