Transport for London says that it will continue to monitor demand before deciding when to reinstate the Waterloo & City line which has been suspended since March.
"There is no timeframe at the moment for when the Waterloo & City line will be operating again," wrote TfL's Melissa Nicols in response to a Freedom of Information request from a regular passenger on the line.
"The expectation is that the line will reopen however it will be a demand-led decision.
"We are closely monitoring the demand forecast impact on the Jubilee and Northern lines (as these are the alternative routes from Waterloo to Bank) to inform us when it would be prudent to restart.
"The train operators [drivers] are also maintaining their route knowledge and all assets are being maintained such that when the restart decision is made, it could be implemented very swiftly."
In normal times the Waterloo & City line – nicknamed 'the Drain' – carries thousands of commuters from Waterloo to Bank in the heart of the Square Mile.
For the latest local news and events direct to your inbox every Monday, you need our weekly email newsletter SE1 Direct.
7,000+ locals read it every week. Can you afford to miss out?
Read the latest issue before signing up