The London Underground strike will go ahead on Tuesday after last-ditch negotiations achieved exactly what everyone feared: nothing. About half of the tube's drivers will walk out, throwing the capital's transport into its usual state of delightful chaos, with a sequel planned for Thursday.

Hopes for a resolution had been cautiously optimistic after a previous strike was suspended in May. But despite 11th-hour talks at Acas between the RMT union and Transport for London (TfL), the dispute over introducing a four-day working week remains unresolved. TfL, ever the optimist, hopes to run about half of all tube services and urged customers to 'check before travel' - a phrase that in London translates to 'prepare for the worst.'

Drivers from Aslef, who represent a slight majority of tube drivers, have actually welcomed the four-day week proposals and will not be striking, limiting the RMT's impact. Still, no service is expected on the Circle or Piccadilly lines, or central sections of the Metropolitan and Central lines. Tube services on functioning lines will finish earlier and later than usual, because nothing says 'improved work-life balance' like unpredictable schedules.

Other rail services - the Elizabeth line, London Overground, and Docklands Light Railway - will run as normal. Buses will operate but are likely to be very busy and slowed by the extra traffic of people who thought 'I'll just drive instead' was a good idea.

The RMT union blamed TfL's 'refusal to engage meaningfully' with concerns over proposed working patterns. A spokesperson said: 'Despite our best efforts in ACAS talks, TfL have failed to provide assurances on our members deeply held concerns around fatigue, reduced flexibility, shift lengths and the impact these proposals could have in a safety-critical role like tube driving.' They added they remain available for talks, but the strike will proceed.

A TfL spokesperson responded: 'It is bitterly disappointing that despite five hours of meetings with the RMT at ACAS and repeated assurances that the four-day working week proposals will remain voluntary, RMT has chosen to continue with its disruptive strike action.' TfL's chief operating officer, Claire Mann, emphasized the proposals are 'completely voluntary' and designed to improve work-life balance, with drivers able to stay on a five-day pattern.

The strikes run for 24 hours from 00:01 on both Tuesday and Thursday - slightly less disruptive than previous walkouts that started at midday and affected four days in April. Business groups noted the damage was already done. Ed Richardson of BusinessLDN said: 'For many businesses that rely on people visiting in person, the impact of these strikes will have already been felt through cancelled bookings and people changing their plans.' He urged both sides to reach a 'sustainable agreement' to end the 'damaging uncertainty' hanging over London's economy - which is to say, please stop making everyone's life difficult.