Schools Secretary Ed Balls defended the Government's record on teenage pregnancies ahead of new figures likely to indicate that a key target will be missed.
Mr Balls said he expected statistics to show that the rate of teenage pregnancies is now the lowest it has been for well over a decade.
However, he conceded that it was going to be "really hard" to achieve the pledged target of a 50% decline on 1998 figures by 2010.
Speaking on BBC Breakfast, the Schools Secretary also defended legislation passed on Tuesday night that will force faith schools to teach sex education.
An amendment to the Children, Schools and Families Bill will mean that religious educators will be allowed to teach personal, social, health and economic (PSHE) lessons "in a way that reflects the school's religious character".
Secularists have criticised ministers for allowing the Bill to be watered down.
Keith Porteous Wood, executive director of the National Secular Society, said: "The Government have once more bowed to pressure from the Catholic Church, betraying the children in faith schools who have a right to objective and balanced sex education."
But Mr Balls told BBC Breakfast that the legislation was an important step forward.
He said: "It is a huge change to make sex relationship education compulsory in every school, including every faith school, for the first time.
"Currently, a faith school can choose not to talk about relationships, to ignore talk about contraception or abortion or any of those thing. That is now going to change. This is not an opt-out at all."