London Tube strikes: What you need to know

A series of six 24-hour strikes by drivers on the London Underground is due to take place, with the walkouts starting later this month.

Members of the Rail, Maritime and Transport (RMT) union voted to oppose the introduction of a four-day working week with condensed hours. The first strike is set to begin on Tuesday 21April at 11:59 BST, when two Tube lines will close entirely.

The union said it was concerned about shift lengths, unacceptable working time arrangements and the possible impact of fatigue on safety.

Transport for London (TfL) described the strikes as "completely unnecessary" and said it was currently trialling a voluntary four-day week for drivers on the Bakerloo line.

When are the Tube strikes?

As it stands, members of the RMT union will strike on:

How much disruption is expected?

No service is expected on the Piccadilly and Circle lines, nor on the Metropolitan line between Baker Street and Aldgate. Central line services will not run between White City and Liverpool Street.

London Underground said there would be "significant" disruption on most Tube lines but the level experienced would not be as severe as the strikes in September.

Boarding the first Tube train may not be possible, according to TfL, with London Overground, the DLR, Elizabeth line, trams and buses expected to be busier.

Only drivers belonging to the RMT union are due to walk out - that is roughly half of the total number of drivers on the network. Aslef's participation in last year's strike with the RMT affected nearly all services.

What is the strike about?

The RMT has rejected an offer for drivers to voluntarily work a four-day week.

Under the proposals, most drivers would see their working week reduced from 36 hours to 35 hours. Their contractual hours would remain the same because paid meal breaks would be introduced.

This effectively means drivers would work longer days, but fewer days each week and fewer overall hours each week.

The arrangement is currently being trialled on the Bakerloo line on a voluntary basis to test its viability.

The RMT said the working day would be too long under the plans, risking driver fatigue and compromising safety.

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

TfL said drivers could remain on a five-day week if they wanted to, pointing out that the change was voluntary.

Could the strikes be called off?

RMT confirmed on Saturday that Underground drivers will strike next week. The union said talks had failed and accused TfL of refusing to make concessions.

The union's general secretary, Eddie Dempsey, said: "We have approached negotiations with TfL in good faith throughout this entire process, but despite our best efforts, TfL seem unwilling to make any concessions in a bid to avert strike action.

"This is extremely disappointing and has baffled our negotiators.

"The approach of TfL is not one which leads to industrial peace and will infuriate our members who want to see a negotiated settlement to this avoidable dispute."

Claire Mann, TfL's chief operating officer, said the proposals allowed it to "offer train operators an additional day off, whilst at the same time bringing London Underground in line with the working patterns of other train operating companies, improving reliability and flexibility at no additional cost".

She added: "The changes would be voluntary, there would be no reduction in contractual hours and those who wish to continue a five-day working week pattern would be able to do so."

London Underground drivers last went on strike in September in a dispute over pay and conditions.

The industrial action caused severe disruption across the capital's transport network, with many Londoners getting around by e-bike instead.