Inconvenient hours often deter mothers from returning to work
Former police constable Michelle Chew has won an appeal against Avon and Somerset Police after they refused her request to work the same days each week.
Miss Chew, 36, a single parent from Taunton, had wanted to work the same days each week to enable her two children to go to nursery.
The tribunal ruled that the force had breached the 1975 Sex Discrimination Act because women were more likely to be looking after children.
These "new rights" could be available to thousands of women in the public and private sectors but firms with small staffs could apply for exemptions.
Some employers fear the costs of trying to reorganise their shift patterns around working mothers.
They say it may cause resentment among other members of staff, who could be forced to work unpopular shifts.
'Trauma'
Fathers could also benefit because firms could face compensation claims unless they give them the same rights.
Miss Chew, who was medically retired from Avon and Somerset Police in August, said she was "relieved" the matter was over.
"I'm very pleased I have made a difference," she said.
"Far too many people go through trauma and having to leave their jobs. I don't think it's understood by other officers, officers without children.
"It needs to be clear it's not just a women's issue, although it was a sexual discrimination case.
"It's about working parents, it talks about mothers' rights but there are men out there who are struggling too."
Dorothy Henderson, employment partner at law firm Travers Smith Braithwaite told BBC News Online: "This is not revolutionary but is consolidating cases that have already happened.
"There has been a trickle of cases and maybe this could open the floodgates for further cases."
She said employers had to be aware of possible legal claims if they changed working hours or shift patterns that had an impact on family life.
Guidelines
The government is expected to announce new guidelines on Tuesday to strengthen the rights of working mothers.
Parents of young children are to win the right to ask for shorter hours at work, in a work and parents report to be revealed by Trade and Industry Secretary Patricia Hewitt.
It will, for the first time, also allow working fathers legal protection in trying to cut hours.
But employers would still be able to refuse parents' requests if they could show commercial reasons why it would be damaging to the business, giving individuals the opportunity to go to tribunal.