Washington Democrats are broadening their inquiry into the circumstances surrounding President Donald Trump’s recent threat to impede the opening of the new Gordie Howe bridge linking Windsor, Ontario, and Detroit. California Representative Robert Garcia and Michigan Representative Rashida Tlaib penned a letter to Matthew Moroun, urging the owner of the neighboring Ambassador Bridge to provide records of any interactions with the Trump administration.

Moroun, whose family has owned and managed the Ambassador Bridge for many years, reportedly met with a member of Trump’s cabinet shortly before the president announced on social media his intention to block the bridge’s opening unless the U.S. secured concessions from Canada, the sole financier of the over $6 billion project.

The Moroun family has a history of opposing the Gordie Howe bridge’s construction as it is expected to impact their toll revenue. Matthew Moroun has been a significant donor to the Republican party and the Ambassador Bridge company has invested heavily in a prominent lobbying firm in Washington closely associated with Trump’s inner circle.

In their correspondence, Garcia and Tlaib focused on Moroun’s political donations, requesting information on any financial dealings he may have had with the Trump campaign or the Republican party. They accused Moroun of leveraging his influence as a donor to the president to prioritize his company’s financial interests over American commerce.

Despite efforts by the Democratic members of the committee, without Republican backing, they lack the authority to compel Moroun’s compliance due to their minority position. Garcia publicized the committee’s investigation and submitted a similar information request to the Trump administration. Michigan’s congressional representatives also urged the president to permit the Gordie Howe bridge to commence operations this year to capitalize on its projected economic advantages.

Moroun has not issued a response to requests for comment at this time.