Londoners have already declared their favourite Tube line, but this ranking of which Tube lines face the most delays may give passengers more food for thought.

Over a year from 1 September 2016 to 1 September 2017, the District Line faced the highest number of days with delays to service (which could include anything and everything from reduced service, minor delays, severe delays, partial line suspension and a full line suspension).

It racked up 244 days with delays, according to a Freedom of Information response published by Transport for London (TfL). That was followed by the Piccadilly, Circle and Central Lines.

Read more: Tube to get more reliable as TfL wraps up major upgrade work

Tube lines facing the highest number of days with delays over a year 1. District – 244 days with delays 2. Piccadilly – 202 days with delays 3. Circle – 176 days with delays 4. Central – 166 days with delays 5. Metropolitan – 143 days with delays 6. Bakerloo – 129 days with delays 7. Hammersmith & City – 125 days with delays 8. Victoria – 97 days with delays 9. Northern – 96 days with delays 10. Jubilee – 88 days with delays 11. Waterloo & City – 66 days with delays

There were five days across the whole year when all lines had good service for the entire day.

The line of choice for less disruption was the Waterloo & City which had 66 days with delays, then Londoners' favourite Tube line the Jubilee with 88 days.

Nigel Holness, director of network operations for London Underground, said: “We carry nearly five million customers every day and work hard to provide them with the best possible service. Last year 96.9 per cent of our trains ran according to schedule, but we recognise that we can still do better.

"This is why we are investing millions of pounds to boost the Tube's reliability and improve journeys for customers. We're undertaking an unprecedented signalling upgrade to improve train frequencies across 40 per cent of the Tube, as well as modernising our busiest stations to vastly increase capacity so people can travel through them more quickly and comfortably.”

TfL has pledged to deliver passengers with quicker and more reliable journeys through upgrades, with completion of significant engineering work over the festive period.

It installed cabling on tracks to support a new Wi-Fi based signalling system allowing trains to run closer together and provide a more frequent service for customers.

A new computer-based signalling and control system between Hammersmith and Edgware Road will be the first section of the Tube to go live with the new signalling system this summer.

The new system will allow trains to run closer together on the Circle, District, Hammersmith & City and Metropolitan Lines, to provide a more frequent service and shorter waiting times for customers.

Read more: Sadiq Khan: Give commuter routes to TfL to tackle "terrible service"