They will also have the chance to take a further three months of unpaid leave, bringing the total amount of parental time-off for couples of newborn children to 12 months.
The intention is to have the legislation in place before the coming general election and the changes will will apply to parents of children due on or after 3 April 2011.
Harriet Harman, the Women and Equalities Minister, said: This gives families radically more choice and flexibility in how they balance work and care of children, and enables fathers to play a bigger part in bringing up their children.
We've doubled maternity leave; doubled maternity pay; introduced paternity leave; more than doubled good quality affordable childcare places; and introduced right to request flexible working.
It is thought that between 4 per cent and 8 per cent of those eligible for the new leave will take it, but that only 1 per cent of small firms will be affected.
Katja Hall, the CBI's director of employment policy, commented: Businesses do their best to support flexible working styles, and this step will give parents more room to adapt childcare to their own situation.
We recognise the need for greater gender equality when it comes to childcare responsibilities, but the government must get these new rules right and not create a bureaucratic tangle.
But Stephen Alambritis of the Federation of Small Businesses argued that the new rules would hamper smaller employers: Small businesses will want all hands to the pump, and having one out of workforce of four means a quarter of your staff being out of action.