The New Hampshire Department of Transportation is taking the next steps toward building a commuter rail line through New Hampshire’s capitol corridor.

A bill allowing the use of federal funds for the development stage of the project became law last week without the governor’s signature.

The DOT will have access to those federal funds starting in September.

During this stage, the state will assess environmental and engineering needs, develop a full financial plan, and engage in discussions with the Massachusetts DOT and transportation authority.

After the development stage, which will take 18 months to two years, the state will be able to apply for a competitive federal grant to fund construction of the project.

The capitol corridor project has been a much-debated topic in the last few years. The DOT has said that the rail would add thousands of jobs, attract new businesses, and improve access to tourism in New Hampshire and Boston.

Gov. Chris Sununu has previously called the project a “boondoggle,” and a bad investment, during his first gubernatorial campaign. He later changed his position when pitching Londonderry as a potential home to a new Amazon headquarters.

The rail line would extend north from Boston, with stops in Nashua and Manchester.