It’s the words no rail passenger wants to hear ... ‘bus replacement service’.

But Network Rail says the engineering works to the Calder Valley Line commencing this Sunday are essential to ensure its reliability for the future.

The line runs between Leeds and Manchester via Bradford Interchange and through Calderdale and the £100m track upgrade will affect weekends until mid-may.

This Sunday the stretch between Bradford Interchange and London Kings Cross will see services diverted via an alternative route between Bradford and Wakefield Kirkgate and will not call at Halifax, Brighouse or Mirfield.

Customers will be directed to bus replacement between Wakefield Kirkgate and Halifax.

Neil Henry, area director for Network Rail, said: “The investment in the Calder Valley line is vital to keep the railway performing reliably as demand for rail services continues to grow. Although there is never a good time to disrupt passengers, fewer people use the railway at a weekend and I advise those who are looking to travel between March and May to plan ahead.”

The works, which will be carried out on weekends until mid-May will see essential parts of the track and the track bed replaced in order to improve the railway’s reliability.

To check your journey go to www.nationalrail.co.uk/service_disruptions