Small business owners have been warned over new laws that have been passed which give fathers the right to six months' paternity leave.

Currently fathers get just two weeks leave after the birth of their child, but the new legislation effectively allows parents to divide the mother's twelve-month maternity allowance between them.

Fathers of children born after 3 April 2011 will be entitled to a maximum of six months' paternity leave, which can only be taken once the mother returns to work. The measure will become law before the general election.

"Small businesses will want all hands to the pump, and having one out of a workforce of four off means a quarter of your staff being out of action," said Stephen Alambritis of the Federation of Small businesses.