Choosing the sex of babies for social reasons will be banned, Health Minister Caroline Flint has said.
Sex selection for 'family balancing' is not popular
The government intends to change the law to outlaw sex selection for non-medical reasons, she said.
Using the method for "family balancing" could be a "slippery slope in terms of people deciding that one gender is more important than the other", she said.
But Lib Dem Evan Harris says it is wrong for the state to restrict the reproductive choice of adults.
Ms Flint made her comments during evidence to the science and technology committee, which is investigating IVF and embryo screening.
She told the MPs that there was some understanding about the use of sex selection of embryos where there was a serious medical condition, but it should not be for "family balancing".
"We will be looking to see how we can make that clear in law so there is a very strong steer to the regulator about how that can be applied," she said.
But Dr Harris, a member of the science and technology committee, said: "Other than the public's 'yuk' reaction, the government gives no reason why parents of three boys shouldn't use pre-implantation sex selection to balance their family.
"Allowing such a move in no way suggests that one gender is better than another and so has no bearing on the negative attitudes to girls in some other countries.
"The state should be giving good reasons before restricting the reproductive choice of adult citizens."
The Department of Health has been conducting a review of the 1990 Human Fertilisation and Embryology Act - the legislation governing human fertilisation.
Advances in medical technology has rendered the act out of date and the government is anxious to update it.
As part of the review, a consultation exercise was carried out, which suggested that the public did not want the sex selection of babies for "social reasons" such as "family balancing".
The Human Fertilisation and Embryology Authority, which regulates this area for the government, has been waiting for a new draft bill containing this provision.
The science and technology committee has also been looking at MPs' calls for an end to the right of fertility clinics to refuse treatment to single women and lesbians.
Currently, clinics must take account of the welfare of the unborn child, including "the need for a father".
Opponents demanded a change in the law, saying the rule discriminates against single women and same-sex couples.
Ms Flint says issues around the "need for a father" were complex and the government was consulting on the issue.