Work-life balance has become the goal of workers under stress, whether from the temporary demands of a deadline or the cumulative effect of juggling professional and domestic responsibilities. The government's plans to extend the right to request flexible working to all parents of children under 16 will add a potential 4.5 million employees to those already working flexibly and will be welcomed by parents who find it particularly difficult to arrange care for older children. Already 90% of companies offer some form of flexible working, largely because they have found that flexi-time, family-friendly hours and job-sharing have been successful in retaining experienced staff after they become mothers. In some organisations, however, the increasing number of staff who work part-time or leave early is starting to cause resentment among colleagues who do not have young children and have to cover for colleagues who do.

A universal right to request flexible working, for which the Trades Union Congress is campaigning, might solve that problem but would be the last straw for many employers and managers in businesses that require staff at unsocial hours. In Scotland, call centres, with hours that extend well beyond the traditional nine-to-five, and tourism-related businesses, whose peak season coincides with school holidays, could find it difficult to accommodate family-friendly working patterns. The Federation of Small Businesses is warning that the combination of more flexible working and new rules improving the rights of agency workers will prove a double whammy for businesses that rely on temporary workers to fill staff gaps. Allowing more parents of older children to work flexibly will improve life for many families, but the success of this policy will depend on how it is implemented.

The crucial part of the proposal is that employers will be able to refuse any request if they can demonstrate a business reason for doing so. Although John Hutton, the Business Secretary, has acknowledged that it is essential that employers retain control over deciding whether flexible working suits their business, the practical difficulty for many will be implementing the policy in a way that is fair to all. There will always be some jobs that require continuity to the point where they cannot be shared or carried out on a part-time basis.

However, the now well-established concept of flexi-time, which allows employees to alter starting and finishing times as long as they fulfil the required number of hours in a week, has been shown to improve performance - and since 2001, when parents of children under six and disabled children were given the right to ask for flexibility, 90% of requests have been granted.

There is no doubt that flexible working is important in attracting staff. That leaves employers with a new work-life challenge: how to balance the needs of the business with the interests of their employees. It can only be achieved by flexibility on both sides.