London, England - Questions should be raised over whether religious veils allow a woman "to be a person in her own right", Cherie Booth said today.
The judge and wife of former prime minister Tony Blair warned that religious and cultural differences should not be used as an excuse for barriers to equality between men and women.
Speaking ahead of a lecture on women's rights at Chatham House in London, Ms Booth told the BBC Radio 4 Today programme it was important not to get "hung up" on the issue of the Muslim veil - which has been at the centre of controversy since cabinet minister Jack Straw said it could be a barrier to understanding.
She accepted the right of women to adopt religious dress if they freely chose to, but raised concerns over whether a woman can fully exercise equal rights if her face is covered in public.
She told Today: "I think we can get very hung up about women's clothes. The question is whether we honour people's religious beliefs or not. Personally, I am happy to honour people's religious beliefs, provided they are freely undertaken.
"Women covering their heads, women dressing modestly, I have no problem with at all. I think, however, that if you get to a stage where a woman is not able to express her personality because you can't see her face, then you do start to have to ask whether this is something that is actually acknowledging the woman's right to be a person in her own right."
Ms Booth said that similar questions could be asked about whether the skimpy clothes preferred by many women in western countries led to them being seen as "sexual objects" rather than people in their own right.
Ms Booth, who outlined her passion for empowering women to have the same educational and career opportunities as men, will use her speech later today to argue that in many cases, unequal gender treatment is due to misinterpretation of religious edicts by male leaders rather than the teachings of the religion itself.
She will cite examples such as unequal divorce rights in Egypt and other Muslim countries and the position of women in orthodox Jewish communities, but she will also stress that Britain and other western countries have less-than-perfect records on issues such as equal pay and the "glass ceiling" on women's careers.
She refused to be drawn on the controversy surrounding the state visit of Saudi Arabia's King Abdullah to the UK in light of human right abuses in his country.
Despite gender inequalities in the desert kingdom, which stretch to a ban on women driving, Ms Booth said it was important to engage in "dialogue", and pointed out that some Saudi women attend university and head businesses.
"We have a lot of progress to celebrate, but the reality is there is still a long way to go, particularly internationally, until we get to the position where women truly are equal to men," she said.
"Women and men are equal human beings and they are deserving of equal respect. That is my bottom line. I think it is the bottom line of the United Nations declarations. But sadly, across the world, that bottom line is often ignored."
Asked about religious restrictions on women's activities, dress and behaviour, Ms Booth replied: "Religion is only as good as the people who interpret the religion and in the course of that, fallible human beings - mainly men - will make judgments which are not necessarily true to the basic principle that men women are of equal value.
"It is clear that the laws of divorce are unfavourable to women in many Islamic countries. One only has to think about the rights to custody of their children, for example, which is based not necessarily on the matter of who is the best parent but on the simple question of the gender of the mother and the gender of the child."