Transport for London is warning that Underground services will start to be reduced from mid-morning, as RMT drivers prepare to walk out for 24 hours from midday. A second 24-hour stoppage is planned from midday on Thursday, and more have been called in May and June. The dispute is about proposals to offer a four-day working week to Underground drivers, who would work longer over the four days but have three days off a week.

The RMT has accused Transport for London of ‘reneging’ on promises to ‘negotiate in good faith’ over proposals for a four-day working week. The union said the first of two pairs of strikes are set to go ahead from midday tomorrow until midday on Wednesday. The second walkout this week is planned between midday on Thursday and midday on Friday. TfL described has the walkouts as ‘completely unnecessary’.