Two Democratic lawmakers on Tuesday expressed concerns about ex-Wall Street financiers overseeing the Commerce Department’s distribution of $39 billion in grants to the semiconductor industry, saying the staffing raised questions about the creation and abuse of a revolving door between government and industry.

In a letter to the Commerce Department, Senator Elizabeth Warren of Massachusetts and Representative Pramila Jayapal of Washington criticized the department’s decision to staff a new office overseeing grants to the chip industry with former employees of Blackstone, Goldman Sachs, KKR and McKinsey & Company.

The lawmakers said the staffing decisions risked an outcome where staff members could favor past or future employers and spend taxpayer money “on industry wish-lists, and not in the public interest.”

Commerce officials have rejected the characterization, describing the more than 200-person team they have built to review chip industry applications as coming from diverse backgrounds including investing, industry analysis, engineering and project management. In a statement, a Commerce Department representative said the agency had received the letter and would respond through appropriate channels.

The criticism highlights the stakes for the Biden administration as it begins distributing billions of dollars to try to rebuild the country’s chip manufacturing capacity.

More than 570 companies and organizations have expressed interest in obtaining some of the funding, and it is up to the Commerce Department to determine which of the projects deserve financing. Biden officials have said they will judge applications on their ability to enhance American manufacturing capacity and national security, as well as benefit local communities.

The department announced its first award from the program in December and another this month, both to chipmakers linked with military procurement. Those awards totaled less than $200 million, but the Commerce Department is expected to begin announcing larger grants in the coming months for major chip fabrication facilities that could range into the billions of dollars.

Given the amount of taxpayer money at stake, scrutiny has turned to the individuals who will be weighing the applications. The director of the chips office, Michael Schmidt, is a former official with the Treasury Department and the New York State government. Other leading staff members have extensive experience in the financial industry, including the chief investment officer, Todd Fisher, a longtime employee of the global investment firm KKR.

Gina M. Raimondo, the commerce secretary, also had a background in venture capital, running her own investment firm before going on to serve as governor of Rhode Island.

The Commerce Department has said that it will take a tough lens to applications and that its awards will be entirely dependent on the strength of applications and their ability to advance U.S. economic and national security interests. Supporters have said staffing the team with investment analysts would give the government the expertise it needs to analyze complex business proposals from chip companies.

“We here at the Commerce Department fundamentally have to be good stewards of taxpayer dollars and provide money only to those projects that need this money in order to incentivize the investment,” Ms. Raimondo told reporters in August.

Some critics have even slammed the Biden administration for imposing too many nonfinancial requirements on chips applicants, like a need to provide affordable child care for their employees.

But in an interview, Ms. Warren said the Commerce Department had created a potential ethical issue “unlike anything I’ve seen before” by deciding to hire a “who’s who of Wall Street’s most powerful firms.”

“This creates an opportunity for gross conflict of interest,” Ms. Warren said.

“This small handful of staffers can use the Wall Street revolving door to provide their former, and potentially future, employers an undue advantage that is not in the public interest,” she said. “They can also benefit those employers’ current clients, or use their position to build relationships and business opportunities with future clients.”

Ms. Warren and Ms. Jayapal’s letter requested more information about the ethics rules the chips office workers were subject to, including whether employees have filed personal financial disclosure forms, and whether the department has established any restrictions on where the employees could work after leaving government.

Ms. Warren and Ms. Raimondo have faced off before, including over the Commerce Department’s meetings with big technology firms. Ms. Warren previously raised concerns about the potential for federal chips grants to be used for stock buybacks or otherwise enrich chip industry executives, and proposed legislation to set firmer limits on the kinds of jobs former officials across the government can take after leaving public service.

In a letter last February responding to a previous inquiry from Ms. Warren about the chips program, the Commerce Department said it had “made ethics a priority in staffing the CHIPS offices.” Employees would be vetted for potential conflicts of interest and receive mandatory ethics training, the department said.