Yesterday in a poor area of south Delhi, I met some girls who were very clear that if the world is serious about development, women must be prioritised. They all agree with the data that shows that without progress on women's rights it will be impossible to make any significant strides forward in the fight to end poverty.

Discussions taking place in Liberia this week will have an important say over how much the world prioritises this in the next 20 years

From grassroots to international level NGOs; to the UN, the World Bank and the OECD, the message is repeated time and time again: gender inequality is a brake on development.

Women make up a majority of the world's population and also a majority - around two thirds - of the world's poor people. Women do 66% of the work and yet earn 10% of the income and own 1% of property.

For all the worst reasons, the enormous problem that is violence against women has received significant attention lately. The attempted murder of Malala Yousafzai in Pakistan followed by the horrific rape and subsequent death of Jyoti Singh Pandey here in Delhi, from where I am writing this piece, have rightly been met with cries of outrage.

As I type, the gathering in Monrovia, Liberia is preparing to discuss the future of development and make recommendations to the United Nations Secretary General on what should happen when the Millennium Development Goals (MDGs) expire in 2015. The 'High Level Panel' is co-chaired by UK prime minister David Cameron, Liberian President Ellen Johnson Sirleaf and Indonesian President Susilo Bambang Yudhoyono.

The successor to the MDGs will, in many ways, shape the priorities for action against global poverty for the next 15-20 years. If they are to have any hope of succeeding, then women's rights and gender equality must be a distinct focus. There must be a standalone goal as well as clear and ambitious targets and indicators on areas like violence against women, as well as under other goals such as education.

Yesterday, in a poor area of south Delhi called Dakshanpuri, I once again saw the reasons for this. Dakshanpuri is a resettlement colony, where the Indian government moved some of the communities who used to live in central Delhi slums. I met two groups of women whose stories and experiences said more than I ever could about why their rights must be at the top of the agenda of prime minister Cameron and the High Level Panel in Monrovia this week.

The first group comprised about 15 middle aged women who have come together to form a voluntary group called a mahila panchayat, supported by one of ActionAid's partner organisations. The mahila panchayat is a kind of community arbitration court which helps women to claim their rights, resolve their problems with men and supports them in accessing the formal justice system, should they need to do so.

Violence is commonplace in the lives of a lot of these women, as are many other forms of discrimination. The women told me of the changes they had enjoyed since becoming a member of the group. One had managed to get inheritance rights to her house in case her husband should die before her, and her own bank account. She told me this in a matter-of-fact way, but it turned out to be something that had taken her years of work.

Another told me of the newfound dignity with which she was treated because she was able to claim her basic rights. I was shown a book signed on a regular basis by men who had left their wives and were now being forced to pay maintenance to their families. The mahila panchayat supervised the men's disbursement of 5000-10,000 Rupees (about £60-£120) on a monthly basis.

One of the women is a trained paralegal and helps women in the community to access the police and court system when the mahila panchayat cannot do the job - for example in the case of a woman who had been brutally and systematically raped by her husband, who did not accept her right to say 'no' to him.

The second group was of around 20 girls in their early teens. They came most days to the community group that ActionAid supports. Many of them spoke some English - in all cases their English was better than my Hindi! They were extremely well informed about their right to education, their right to live free from violence and their basic right to dignity. They were concerned about sex-selective abortions which are causing the birth rate of women in India to decline because a boy child is often valued far more than a girl. Their knowledge and their support of each other in claiming their rights made a practical difference to their lives in areas like the length of time they would be able to stay at school, in stopping their brothers from beating them and in whether they would continue to work when they got married. After talking about why the dowry, or bride price, was so wrong, one sang a beautiful song about how she was worth more than money.

By working together, and with the support that aid and development NGOs like ActionAid can bring, all of the women I met in Dakshanpuri were changing their own lives, the lives of their sisters and daughters, and the culture in their community.

Across the world, there are millions like the women and girls of Dakshanpuri. The girls asked me whether there was any discrimination against women in the UK. I told them that things were better than in India but that even now, two women a week die from domestic violence, that women are paid less than men for equal work, and that we are vastly under-represented in Parliament. They expressed surprise and asked what we could do together to change this situation?

Part of the answer lies with David Cameron and the rest of the High Level Panel as they meet this week in Monrovia.

To his credit, David Cameron has promised that he will "personally ensure that the fight for the empowerment of women is at the heart" of the post MDG process. Justine Greening, secretary of state for international development, has been clear about her desire to prioritise women and girls in DFID's future work. And just this week, Ivan Lewis, shadow secretary of state for international development, gave an impressive speech in which he argued strongly in favour of a standalone goal on women's rights and gender equality in the post MDG framework.

Let us hope that this week's outcome in Monrovia gives an adequate response to the girls of Dakshanpuri: to make women's rights a clear and distinct focus in the framework that will define the next two decades in international development.

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