On 7 March 2019, the Queen hosted a Buckingham Palace event to mark the 50th anniversary of Charles's investiture as the Prince of Wales. Guests at the event included the Duchess of Cornwall, the Duke and Duchess of Cambridge, the Duke and Duchess of Sussex, Prime Minister Theresa May and Welsh First Minister Mark Drakeford.
On 18 March 2019, the Speaker (Speaker of the House of Commons) informed the House of Commons that a third meaningful vote could be held only on a motion that was significantly different from the previous one, citing parliamentary precedents going back to 1604.
After the government deemed unwarranted the concerns over the legality of the proposed change (because it contained two possible exit dates) the previous day, on 27 March 2019 both the Lords (without a vote) and the Commons (by 441 to 105) approved the statutory instrument changing the exit date to 22 May 2019 if a withdrawal deal is approved, or 12 April 2019 if it is not. The amendment was then signed into law at 12:40 p.m. the next day.