MPs have voted to suspend a former Conservative trade minister from Parliament for seven days.
Conor Burns had attempted to intimidate a man involved in a financial dispute with his father by using parliamentary privilege and making threats, the Commons standards committee said.
Mr Burns resigned from the government last week.
He is barred from the parliamentary estate and unable to take part in debates during his suspension.
The standards watchdog recommended his suspension after it found he had made “veiled threats” and attempted to use his parliamentary privilege to “further his family’s interests”.
In February, Mr Burns used House of Commons stationery to write to the chairman of a company with whom his father was in dispute over the repayment of a loan.
He had written: “I am acutely aware that my role in the public eye could well attract interest especially if I were to use parliamentary privilege to raise the case.”
Parliamentary privilege protects MPs from being sued for defamation for speeches made in Parliament.
In a letter to Boris Johnson after his resignation, Mr Burns accepted the sanction and gave the prime minister his full support.
In a separate case, international trade minister Greg Hands apologised to the Commons for using parliamentary stationery to send a letter to thousands of his constituents in April 2019.
Mr Hands, the Conservative MP for Chelsea and Fulham, said he accepted the letter did not conform with the House’s rules.
He told the Commons: “I believe the rules in question are in need of updating to reflect the fact that combining different communications into one single letter can save money and staff time.
“Nonetheless, I’m sorry for the length of time this investigation has taken and do accept that I at the time acted outside of the current House rules.
“I am therefore taking the earliest opportunity to offer the House my apology both for the initial breach of the rules and for insisting on an unnecessary reference to the committee thereby extending the length of the inquiry.”
Mr Hands said he would reimburse the cost of sending out the letter, which was just under £4,900.