The Waterloo & City line will reopen today for the first time since the start of the pandemic, Transport for London (TfL) has announced.
The important London commuter link, which connects Waterloo and Bank stations in the centre of the capital, closed in March 2020.
Services will now run every five minutes Monday to Friday from 6am to 10am and 3.30pm to 7pm.
TfL said the operating hours will enable customers to stagger their journeys during rush hour and provide extra capacity for people who have to travel at peak times.
The line had been due to reopen on June 21 this year.
Mayor of London Sadiq Khan said: “I’m delighted that the Waterloo & City line is returning from today, ahead of schedule.
“As London’s economy continues to reopen and more people return to the offices, having this key artery connecting Waterloo and Bank stations up and running will be vital.”
During the pandemic, Waterloo & City line Tube drivers were drafted onto the Central Line to help manage the extra services required to ensure social distancing was maintained.
TfL said the number of people using the Tube had increased by more than 20% since May 17.
Catherine McGuinness, policy chairwoman at the City of London Corporation, said: “Today’s reopening of the historic Waterloo & City line is an exciting and vital moment in the Square Mile’s recovery as it marks a huge step on our journey back to normality.
“The Waterloo & City line will support the return of the City’s commuting workforce back to the Square Mile as the easing of restrictions allows.
“The additional footfall generated will also provide reassurance to the many businesses that rely on commuter traffic for trade.”
TfL said there will be occasions when social distancing is not possible as more people return to using the network, and advised people to consider waiting for the next service when necessary.
Face coverings must still be worn across the transport network.