The guards will not book on for shifts due to begin between 00:01 and 23:59 on Friday May 27, Friday June 3, Friday June 10 and Friday June 17.

"This dispute is about ensuring that there is a safety-trained guard in each portion of a multiple unit train," RMT general secretary Bob Crow said today.

"It is simply not possible for one guard to cover the whole of a multiple-unit train because there is no access between the units when the train in moving.

"Midland Mainline have ignored our attempts to negotiate on this crucial safety issue despite a work to rule and rest-day and Sunday-working bans, and our members have now voted by a margin of nearly seven to one strike.

"This action is about safety, pure and simple, and I hope that those who rely on Midland Mainline?s services will join with us in urging the company not to subordinate safety standards to cost-cutting.

"It is time for the company to recognise the strength of feeling on this matter, remove its head from the sand and talks to us," Bob Crow said.

ends

Note to editors:In the ballot of around 150 RMT guards, 70 voted for strike action and 13 against.