Why are Tube strikes happening and how much disruption will there be?

Drivers who are members of The Rail, Maritime and Transport union (RMT) will walk out for 24 hours from midday on Tuesday and Thursday.

They are the first walkouts in a series of six 24-hour strikes by drivers on the Tube.

But why are the drivers striking, when are they and how much disruption can passengers expect? Here is all you need to know.

As it stands, members of the RMT union will strike at the following times (all BST)

Transport for London (TfL) are offering Tube drivers the chance to work a four-day week, but the RMT has rejected the offer.

Under the plans the majority of drivers would see their working week reduced from 36 hours to 35 hours – but they would work longer shifts on days they work.

But the RMT argues the working day would be too long under the proposals, risking driver fatigue and potentially compromising safety.

The union instead wants to negotiate a 32-hour week over four days for drivers, meaning they would work three fewer hours each week for the same salary.

TfL is currently rejecting the RMT proposals, saying drivers do not need to take up the four day week offer and could remain on a five-day week if they want.

Members of the Aslef union have also already voted to accept TFL’s four day week offer.

All London Underground lines will be affected by the Tube strikes between April 21 and 24, TfL has said.

No service is expected at all on the Piccadilly and Circle lines during the strikes.

A reduced service will run across other lines but “significant disruption” is expected.

Any services that do run will be less frequent, very busy, and you may not be able to board the first train, TfL is warning.

No service is expected on the Metropolitan line between Baker Street and Aldgate

No service is expected on the Central line between White City and Liverpool Street

Outside of the specific strike times disruption is also expected.

While normal services will be expected until mid-morning on the Tuesday and Thursday, services will then begin to ramp-down before the 24-hour strikes.

Tube services that do run on Tuesday and Thursday will finish early – you should aim to have completed your journey by 8pm, TfL has said.

On the Wednesday and Friday, significant disruption will take place on all lines until midday.

Tube services that do run will start later than normal with no service expected before 7.30am on Wednesday and Friday.

In the afternoon on those days some disruption is expected until the evenings.