(Sharecast News) - London Underground drivers belonging to the Aslef union will walk out in April and May, it was announced on Wednesday.

The decision came on the heels of a resounding mandate from members of the union, with 98% voting in favour of industrial action.

With a 70% turnout in the ballot, Aslef said its drivers would stage 24-hour strikes on 8 April and 4 May.

"Despite a previous commitment to withdraw plans for massive changes to drivers' working conditions, London Underground management has established a full-time team of managers preparing to impose their plans," said Finn Brennan of Aslef.

According to the BBC, the discord stemmed from proposed alterations that would see drivers working longer shifts, spending up to 25% more time in the cab, and the removal of existing working agreements.

"It's about getting people to work harder and longer for less," Brennan added.

Transport for London (TfL) had not commented by midday on Wednesday.

Reporting by Josh White for Sharecast.com.