Minister Conor Burns has resigned from government after a watchdog concluded he had attempted to "intimidate a member of the public" by using his privileged position.
The House of Commons Standards Committee had recommended Mr Burns be suspended from the Commons for seven days after investigating a complaint that he attempted to secure a payment to his father by saying he may use parliamentary privilege to raise the issue in the Commons.
Recommending the seven-day suspension, the committee said it considers that the "abuse of his privileged status" calls for a "sanction more severe than apology".
Former international trade policy minister Mr Burns announced his resignation with "deep regret" on Twitter shortly after the suspension was recommended.
The MP for Bournemouth West said Prime Minister Boris Johnson will "continue to have my wholehearted support from the backbenches".
The committee found that the MP "used his parliamentary position in an attempt to intimidate a member of the public into doing as Mr Burns wished".
It said Mr Burns became involved in a "dispute relating to purely private family interests which had no connection" with his parliamentary duties.
He "persisted in making veiled threats to use parliamentary privilege to further his family’s interests even during the course of the commissioner’s investigation, and that he misleadingly implied that his conduct had the support of the House authorities”, the committee said.
A Downing Street spokesman said: “Conor Burns has resigned as Minister of State for International Trade following a report from the Parliamentary Commissioner for Standards.
“A replacement will be announced in due course.”