London: Queen Elizabeth made a surprise appearance at a ceremony to mark the completion of a long-awaited London train line named in her honour.

Elizabeth, wearing a bright yellow hat and coat and using a walking stick, unveiled a plaque at Paddington Station. She was joined by her son Edward and Prime Minister Boris Johnson.

She was then given a commemorative Oyster card and shown how to use it by Kofi Duah, 24, a customer experience assistant.

Duah said: “She asked, ‘Where can it take you to?’ I said, ‘It can take you on all the lines, from Paddington to Abbey Wood.’”

The Queen, who was using a walking stick, returned to Buckingham Palace for lunch instead of trying out the trains. Prince Edward became the first passenger, travelling to Tottenham Court Road and back.

It is the latest public outing for the 96-year-old monarch who, despite missing a speech in parliament last week due to mobility issues, twice attended a horse show at her Windsor Castle residence in recent days.

“In a happy development Her Majesty The Queen is attending today’s event to mark the completion of the Elizabeth line,” a Buckingham Palace spokesperson said.

The $24 billion rail project was originally due to be opened in December 2018, but had been repeatedly delayed by issues with safety testing and signalling systems, even before the onset of the pandemic.