The Deputy Prime Minister will this morning outline plans to allow couples to share maternity leave.
The change in April allows fathers to take up any remaining unpaid leave if their partners go back to work early.
Nick Clegg will denounce the current arrangements as "Edwardian".
He will also say the government will consult on a "proper" system of shared parental leave to be introduced in 2015.'Alarm Clock Britain'
In the speech Mr Clegg will say it is vital that reforms to parental leave help not only the rich, but also ordinary working families in what he calls "Alarm Clock Britain".
"Too many of these parents feel trapped by the current rigid rules," he will say. The current systems which allow men two weeks of paternity leave "patronise women and marginalise men" he will claim.
The government wants couples to be able to take leave in a number of chunks rather than a single block, or parents taking time off together rather than one after the other.
The change allowing men to use unpaid leave not used by their partners was originally proposed by the previous Labour government. It will come in later this year.