New flexible working rules are helping parents to see more of their young children - but may make many families worse off, a survey has suggested.
Government figures show almost eight out of 10 employees had their requests for flexible working granted.
But the poll by Maternity Alliance reveals those who ask for flexible working practices often have to accept a pay cut or drop in job status.
The survey found a quarter of parents were unaware of last year's law change.
The new rules say parents with a child under six can ask employers for a change in working hours, day or location of work, provided they have been with the employer for six months.
The employer can only refuse for a number of specific business reasons.
The poll found 68% of parents who asked had their request accepted, while requests from 25% were turned down.
These included such minor changes as arriving or finishing 15 minutes early.
Nine out of 10 of those parents whose requests were refused said it was done for unjustified reasons. 'Heavy workloads'
Trade and Industry Secretary Patricia Hewitt, also Minister for Women, said she hoped support for flexible working would encourage more parents to raise the issue.
She said: "With more women in work than ever before, employers cannot afford to ignore the benefits of flexible working, including recruitment, retention and staff morale."
But Maternity Alliance said while 25% of parents said their working conditions had improved, 27% said their situation had worsened.
Liz Kendall, Maternity Alliance director, said the government's 2006 review of the system must address these problems.
"Many parents feel forced to accept a cut in salary or job status in order to secure at least some flexibility in their work," she said.
"Others continue to struggle to juggle long hours and heavy workloads or decide to give up work completely."
Dave Prentis, general secretary of public service union Unison, said they had wanted the legislation to give employees the right to flexible working, not the right to ask.
"Our fear was that most employers would find a reason to refuse.
"Unfortunately these fears are borne out by this survey, which shows that employers are turning down reasonable requests for more flexible working."
Meanwhile, parental rights campaigners Fathers Direct are urging the government to increase paternity leave pay to 90% of earnings, up from the current ?100 per week. BBC News