London Underground is gearing up for the return of thousands of City workers with the reopening of “the Drain” between Waterloo and Bank stations.

The Waterloo & City line, which has been shut for 14 months, will reopen on June 21, Transport for London said.

The line was opened in 1898 and became known for long queues at the country’s busiest rail station as workers scramble to make it into the office in time.

It carries 15m passengers annually and is the second busiest after the Victoria line.

Tube bosses will put on an extra peak service to cater for bankers, lawyers and accountants unable to adjust their working hours.

Catherine McGuinness from the City of London Corporation said: “The reopening of the historic Waterloo & City line is vital to the Square Mile’s recovery. Many more people will return to the City as soon as the rules allow.”

Meanwhile, rail companies will add 2,500 more daily services on Sunday as lockdown rules are relaxed the following day. The Rail Delivery Group said this is the largest increase in capacity this year.

The amendment will be implemented on Sunday in one of two major annual shake-ups of timetables.

Department for Transport data shows rail travel across Britain was at 38pc of pre-pandemic levels on May 3, which is the latest date with confirmed figures.

However, demand is expected to increase from Monday when coronavirus rules are eased.