By John D. McKinnon and Brent Kendall

WASHINGTON -- The Justice Department and a group of state attorneys general are scheduled to meet Friday to talk about next steps in bringing a likely antitrust case against Alphabet Inc.'s Google, according to people familiar with the matter.

Federal and state officials are expected to meet virtually to talk about the scope of any legal complaint against the search giant, as well as the states' current thinking on joining a Justice Department lawsuit or setting out on their own, the people said.

The Wall Street Journal reported last month that both the Justice Department and a group of states are likely to sue Google on allegations that the company is using its dominant position to suppress competition, and are well into litigation planning. The Journal reported that the department's lawsuit could come as soon as this summer. That remains the current timeline, the people said.

Google has repeatedly denied that it runs its businesses in an anticompetitive manner.

"We continue to engage with the ongoing investigations led by Attorney General Barr and Texas Attorney General Paxton," a Google spokeswoman said. "Our focus is firmly on creating free products that help Americans every day and lower costs for small businesses."

Because Google holds a powerful position in several markets, one key question for any government case is how much of the company's conduct antitrust enforcers are prepared to challenge.

One focal point has been Google's online advertising business, where the company owns the dominant tool at every link in the complex chain between online publishers and advertisers.

The Justice Department has been preparing to challenge Google's ad-market conduct and also wants to address broader concerns that Google uses its dominant search business to stifle competition, the Journal has reported.

Details of the department's thinking couldn't be learned.

It isn't clear how many states will participate in Friday's discussion. And while most states have raised concerns about Google, it's not clear whether they are all on the same page about how to proceed.

Wall Street Journal publisher News Corp is a longtime Google critic and is among a group of the publishers that have been contacted by antitrust investigators.

Two U.S. senators, Josh Hawley (R., Mo.) and Richard Blumenthal (D., Conn.) wrote a joint letter to the Justice Department in March, urging investigators to probe Google's dominance in search as well as its ad tech business. Noting Google's large market share in search, they said its "opportunities for anticompetitive conduct are substantial" and evidence suggests it has obtained market share through "illicit means."

That includes manipulating search results to favor its own products at the expense of others, they added. Companies that operate vertical search platforms for services such as travel and restaurant ratings have been among those complaining.

"The evidence of anticompetitive conduct in search technology is striking, and deserves scrutiny," Mr. Hawley said on Tuesday. "I'm optimistic DOJ will do its due diligence and follow the facts."

Some conservatives recently stepped up calls for the Justice Department to make Google's alleged viewpoint bias a part of their investigation into the company's search and advertising businesses.

"Both the American free market and the openness of our democracy are presently at stake," Sen. Marsha Blackburn (R., Tenn.) said in a letter to Mr. Barr on Monday. "As the Department decides which actions to pursue, I urge mounting a full investigation that examines the company's control over vast sectors of the Internet economy, from online advertising to online search."

Mr. Barr sounded sympathetic in an interview over the weekend on Fox News:

"They [tech companies] are only presenting one viewpoint and they can push the public in a particular direction very quickly," he said. "One way this can be addressed is through the antitrust laws and challenging companies that engage in monopolistic practices."

Critics of using antitrust law to address alleged viewpoint bias say it risks violating free-speech principles and turning antitrust law into a political weapon.

"If private platform power over the speech environment is a problem, antitrust is the wrong solution," wrote two Charles Koch Institute officials, Neil Chilson and Casey Mattox, earlier this year in a paper for the Knight First Amendment Institute at Columbia.

Write to John D. McKinnon at john.mckinnon@wsj.com and Brent Kendall at brent.kendall@wsj.com