WASHINGTON (Reuters) -Three Democrats on the House Energy and Commerce Committee raised serious concerns about T-Mobile's involvement in the Trump Organization's self-branded mobile service and a $499 smartphone dubbed Trump Mobile.

Representative Frank Pallone, the ranking member of the committee and two other committee members, asked T-Mobile CEO Mike Sievert to answer questions about the company's dealings with the Trump organization. "We are specifically concerned that T-Mobile's business relationship with the Trump Organization - while Donald Trump is serving as President of the United States - presents a conflict of interest that will harm the American people," they wrote in a letter Wednesday.