Clegg has said that he had considered extending paternity leave from the current two weeks, but concern had been voiced within Government and from business groups about the cost.
Flexible leave will be reviewed by 2018, when extending paternity leave will be looked at, Mr Clegg is expected to announce.
These are major reforms and, at a time of continuing economic difficulty, it's sensible to do them in a number of steps, rather than one giant leap. More and more men are taking on childcare duties, or want to, and flexible leave builds on that.
More top news
An orangutan who has lived in a zoo for the past 20 years, can be granted basic human rights, a court in Argentina has ruled.
Socialite Tara Palmer-Tomkinson has been cautioned by police after a 'disturbance' at Heathrow Airport.
The NHS is to set up 11 centres to unlock the secrets of DNA and help develop tests and drugs to target cancer and rare genetic diseases.