The Arlington County Board plans to vote Saturday afternoon on giving Amazon $23 million and other incentives to build a headquarters campus in Crystal City, but only after hearing scores of northern Virginia residents and advocates testify for or against the project.

The five-member board is expected to support the plan, which was announced amid much hoopla on Nov. 13. The proposed county incentives are part of an agreement in which Amazon would occupy significant office space and bring at least 25,000 high-paying jobs to Arlington in coming years.

Opponents hope to postpone the vote until after additional public hearings, where they want representatives of the online retail giant to answer questions directly from anyone in the community.

The Saturday hearing was scheduled to begin no earlier than 1 p.m. and last several hours before the vote. Ninety-one people signed up in advance to speak on the topic.

In the four months since Arlington won a much-publicized, nationwide contest to attract the facility known as HQ2, Arlington residents have been asking questions about its impact on their community.

People have looked at the county’s five online Q&A sessions 14,000 times, and about 400 attended community events to discuss the provisions in the Amazon agreement. Board members and county staff also met with scores of civic organizations, served on multiple panels and appeared on television, online and in news articles to discuss the deal.

Both Amazon and the real estate company JBG, the main contractor for the project, have met with business groups, school leaders, 50 nonprofit groups and others. However, these sessions have not satisfied critics’ calls for an open public meeting for anyone with questions or criticisms. (Amazon founder and CEO Jeff Bezos owns The Washington Post.)

Most Arlingtonians, northern Virginians and residents of the Washington region support Amazon’s arrival, several surveys have found. Business organizations, universities and nonprofit groups came out strongly for the deal.

But a small, vocal group of activists has sought to block the project, saying that the county and commonwealth should not give any incentives to one of the world’s most valuable companies. They also have demanded housing and job protections for existing residents.

These opponents — including left-wing organizations and immigrants groups — felt empowered after Amazon canceled plans last month to build a headquarters facility in New York City, also with 25,000 jobs. The company withdrew after criticism of the plan from some elected leaders, unions and community activists.

In Virginia, however, such opposition did not appear to catch fire among the broader public.

Officials estimate that the Amazon project’s net fiscal impact on Arlington could be worth additional revenue of $162 million over 12 years and $392.5 million over 16 years.

The incentives agreement promises the world’s largest online retailer cash grants estimated at about $23 million if it occupies 6.05 million square feet of office space in Crystal City and Pentagon City through 2035.

The money would come from an expected increase in the hotel, motel and lodging tax paid by visitors; Amazon would get up to 15 percent of that increase, pegged to how much floor space is in active use by the company each year from 2020 to 2035.

Amazon’s offices will be located within an already-established special tax district where a portion of the property tax revenue goes toward infrastructure improvements such as parks and wider sidewalks.

The incentive agreement says that half of any new revenue from that district starting in 2021 will go specifically toward improvements around the Amazon buildings for the following 10 years. That grant is worth an estimated $28 million but the county says it’s not a grant just for Amazon, because the improvements will benefit other companies in the immediate area. Amazon will have a chance to express its opinion on how the county uses the money, although the board will make the decision.

The county also offered Amazon the possibility of using its fast, fiber-optic network connection, which would be the subject of a separate agreement if the company chooses to use it.

It’s not yet clear whether Amazon will pay the local business license tax because that tax is levied only on certain types of business, and Amazon has not yet announced which of its business units will be based in Arlington. If the company does pay the license tax, then some of its operations could be eligible for a discount of up to 72 percent under an existing program designed to attract technology companies.

While Arlington pored over the details, the Virginia General Assembly passed, and Democratic Gov. Ralph Northam signed, an incentives package worth up to $750 million for Amazon.