RAIL unions will have to make crucial decisions today on whether to call strikes over Easter, as talks continue with Network Rail in a bid to resolve two disputes.

But the discussions have been complicated by the revelation that the ORR has served a improvement notice on Network Rail concerning health and safety breaches affecting bridges in Kent, Anglia and Wessex.

Both the RMT and TSSA have gained legal authority to stage walkouts following strike ballots involving more than 20,000 staff. The main dispute is over the loss of 1,500 maintenance jobs, but signallers are opposing plans for more flexible rostering, which would mean a gradual reduction of popular 12-hour shifts.

Staff on these shifts are only required to work for Network Rail three days a week, but NR chief executive Iain Coucher says such long shifts are not appropriate for larger panel boxes and major signalling centres, which are set to replace the majority of the remaining small boxes in years to come.

He is also denying union claims that safety would be put at risk by the job cuts, most of which have already been achieved through voluntary severance. He is continuing to resist union calls for a permanent undertaking that there will never be any compulsory redundancies.

After an apparent deadlock last week, talks have now restarted at ACAS, but the unions must make any Easter strike decisions now, because the law requires seven days' notice of walkouts. The RMT Executive has already confirmed that it will be meeting today to decide its next move.