The Queen has made a surprise visit to Paddington Station to unveil a plaque commemorating the completed Elizabeth line.
Transport for London (TfL) has confirmed the long-delayed project, also known as Crossrail, will open to the public on Tuesday, May 24.
Ahead of the planned opening, the 96-year-old monarch and her youngest son Prince Edward, the Earl of Wessex, visited Paddington Station earlier today (Tuesday, May 17).
The royals were welcomed by prime minister Boris Johnson, London mayor Sadiq Khan, transport secretary Grant Shapps and TfL commissioner Andy Byford.
The Queen was heard chatting with station staff during the official visit and loading money onto a limited edition Elizabeth Line Oyster card.
It comes just two weeks before the Platinum Jubilee celebration which will see her mark 70 years on the throne, as the UK’s longest reigning head of state.
A Buckingham Palace spokeswoman said: "In a happy development, Her Majesty The Queen is attending today’s event to mark the completion of the Elizabeth line.
"Her Majesty was aware of the engagement and the organisers were informed of the possibility she may attend."
The Queen arrived just after 11.30am, and wore a matching yellow coat and hat.
Prince Edward and his mother met Crossrail staff, train drivers, TfL workers and apprentices.
She unveiled a plaque stating that she had officially opened the new line, and spent ten minutes in the station, before departing.
After her departure, the prime minister said: "We’re all incredibly touched and moved and grateful to Her Majesty for coming to open the Elizabeth line today.
“It was fantastic to see her."
Prince Edward then rode on the Elizabeth to and from Tottenham Court Road, which he reportedly said was “good fun”.
Mayor Sadiq Khan wrote on Twitter: “A real honour to have Her Majesty the Queen and Prince Edward, Earl of Wessex, join us this morning for the official unveiling of the new Elizabeth line station at Paddington.
“London: one week to go until the Elizabeth line opens!”
The Crossrail project was due to be completed in December 2018 with a £14.8bn budget.
However, the cost of the scheme has since spiralled to around £18.9bn, including a £5.1bn cheque from the government.
But TfL says the new line will boost capacity and cut journey times across the capital.
The line traverses from Reading and Heathrow Airport, to Shenfield, Essex, and Abbey Wood, south-east London.
A full timetable will not be in place until May 2023 but central London services will run every five minutes between 6.30am and 11pm from the opening date.