Council services across the Spen Valley could grind to halt in a union dispute over equal opportunities for workers.

The Council has decided to change the way it advertises jobs in a bid to give its employees more chance for promotion.

But the public service union, Unison, which represents 8,000 Kirklees Council workers, says the move amounts to "favouritism".

Paul Holmes, Kirklees Unison branch secretary, said: "This decision is the worst possible. While some may think Kirklees Unison members would want jobs advertised internally, nothing could be further from the truth."

The vast majority of Unison members got their jobs at the Council through external advertising, he said. The new policy will be reviewed after 12 months and will see many jobs being advertised solely to current Council staff.

A Council spokesman confirmed some positions would still be open to external applicants out of necessity.

In some circumstances if only a small number of Council candidates have come forward, the job may still be thrown open. It is hoped this method will encourage career development, give the Council greater flexibility and save costs on advertising.

Council leader Councillor Kath Pinnock said: "We felt that when jobs were being advertised all the time regardless, you raise people's hopes. The whole purpose is to put some flexibility into the system. We will still hold job fairs for people wanting to work in social services and building services, encouraging people to come along and be given help in filling out application forms.

"It should open up the process."

Mr Holmes said Unison was in favour of equal opportunities, meaning jobs being open to the whole community, not just Council staff.

"Kirklees has a diverse community and it is vital that the largest employer in Kirklees sets an example. While it may seem to serve our members' interest for positions to not be advertised externally it doesn't. Unison members don't want this favouritism.

"They want to get jobs through a transparent, fair and open process. We will be urging our members to vote for industrial action to help preserve integrity and equal opportunities in local government."