New rights aimed at promoting flexible working for parents could be divisive and have a negative impact on staff who do not have children, according to a new report today.

A survey of 28 major organisations, employing almost 750,000 workers, showed that most already had policies in place to deal with requests for flexible working.

Three out of four said new legislation coming into effect next month would not make them more likely to grant a request to work flexibly.

Most of those surveyed by law firm Linklaters and campaign group Parents at Work said the impact of the new law on their business would be minimal.

The new right for parents of children under the age of six to ask for flexible hours will probably raise awareness of flexible working options.

But the report voiced concerns about increased bureaucracy and the potential divisiveness of the legislation.

Raymond Jeffers, head of employment at Linklaters, said: "On the positive side, the new legislation is likely to raise awareness of good flexible working models.

"On the negative side, the new law is likely to require a more bureaucratic process than most employers' less formal practices. Also, as the legislation is aimed at one small group of parents that fit the criteria, that could possibly lead to division in the workplace."

Meanwhile, the vital role fathers play in the development of their children is being discussed at a conference this week.

Evidence has shown having fathers present as children grow up can improve their health and educational achievements while also taking pressure off mothers.

The week-long summit in Oxford is the first to specifically examine the role of fatherhood.

Leading experts will decide on policies to promote the role of fathers, which will be presented to the UN next year.

The Equal Opportunities Commission recently published a report showing UK fathers were spending more time with their children.

In the mid-Seventies, fathers with a child under five spent less than 15 minutes a day with them. This figure had risen to two hours a day by the end of the Nineties.

The Government will introduce new rules next month giving fathers two weeks' statutory paid paternity leave.

Trade and Industry Secretary Patricia Hewitt welcomed the summit as an "important step forward for families".

Duncan Fisher, chief executive of Fathers Direct, which organised the summit, said: "This summit is an opportunity to exchange experiences from around the world."