Tube drivers are set to push ahead with strikes starting on Sunday after talks with London Underground bosses broke down this week.

The four strikes are set to kick off on June 19, 27 and 29 and July 1 in response to the sacking of Northern line driver Arwyn Thomas.

However, London Underground has promised a “near normal” service on the first days of the walkout.

The Rail Maritime and Transport Union (RMT) instigated the strikes after London Underground refused to reinstate Thomas, who is awaiting the results of an employment tribunal.

Transport for London has hit back at RMT, arguing it is premature to strike before the conclusion of the hearing.

The first walkout will start at 9pm on Sunday June 19 and run until 3am on Monday June 20.

The following walkout will be at 9pm on Monday June 27 until 11.59am on Tuesday June 28.

The third strike starts at 12pm on Wednesday June 29 and runs until 11.59am Thursday June 30.

The final strike will be at 12pm Friday 1 July until 9pm that day.

The union had previously ordered five strikes in protest over the sacking of Bakerloo line train driver Eamonn Lynch and Arwyn Thomas.

However, these were later called off.

Lynch, who was sacked over a train safety issue, was later found to have been unfairly dismissed by an Employment Tribunal and reinstated into a non-driving job.

Thomas was sacked for alleged “abusive behaviour” towards his colleagues, a charge he denies. He is now awaiting the results of an Employment Tribunal at the end of this month.

The union claims the “real reason” behind the sackings was because both men were admitted long-standing union activists.

RMT general secretary Bob Crow said: “The facts in Arwyn Thomas’s case could not be clearer and with the rolling action due to start this weekend I would appeal again to London Underground to see sense, abide by the spirit of the agreement we reached with them weeks ago over these vitimisations and get Arwyn back to work doing what he is being paid to do - drive tube trains.

“This trade union would not be worth its salt if we didn’t stand up and fight injustice and Arwyn Thomas’s case is probably the clearest cut case of victimisation on the grounds of union activities that you will ever see. The chair of the interim tribunal found exactly that when LU were invited to adjourn for fifteen minutes and re-employ - it is a tragedy for Londoner’s and for industrial relations on the tube that they blew that opportunity.”

London Underground managing director, Mike Brown, said: “This strike action will achieve nothing and I urge the RMT leadership to calmly await the outcome of the employment tribunal without any further strikes. I have given a cast-iron assurance that if the tribunal rules that we should re-instate or re-engage Arwyn Thomas, then we will do so. We have given that assurance in writing before this strike action and I make it again now, so there can be no justification whatsoever for the RMT to continue to threaten Londoners with strike action.”