On 1 May it will be the 20th anniversary of 101 Labour women being elected to parliament. This transformed not only the face of the Commons, but the agenda of politics and the work of government. Their arrival at Westminster in 1997 was to be the start of a whole swath of changes to back women up in their changing lives.

Now we live, once again, under a Tory government which means all that progress for women is stalling, and there is a threat that the clock will be turned back. There are protests all around the country as children’s centres are cut back, tax credits cut and support for victims of domestic violence reduced.

When I was elected in 1982, only 3% of MPs were women and I was one of only 10 female Labour MPs. Women’s voices were not heard in parliament and women in the country could not see their concerns reflected on the political agenda. We believed that we needed to do three things: transform our policy agenda so that it reflected women’s concerns, get more women elected as Labour MPs and ensure that Labour’s frontbench team included women as well as men.

We knew that good as our policies for women were, so long as Labour remained male-dominated, women would be reluctant to vote for us and we would continue to languish in opposition, unable to end the suffering that was being caused by Margaret Thatcher’s government.

We began by arguing for a woman to be on every shortlist where a Labour MP was retiring. Although the rule change was made, bringing an end to all-male shortlists, men still got selected to replace male Labour MPs. So we argued for half of those on shortlists to be women. It was controversial, and, again, failed to get women selected. So we argued for half the seats where men were retiring and half the seats we hoped to win to be reserved for women. This was hugely divisive and criticised as discriminatory. But it went through Labour’s conference in 1993 and paved the way for there to be Labour women candidates in every region of England and in Scotland and in Wales who then went on to win in 1997.

‘We needed to ensure that Labour’s frontbench team included women as well as men.’ Photograph: PA

It was not, though, enough just to have women as candidates. We needed women to be leading spokespeople for the party and in the shadow cabinet. At that time, the parliamentary Labour party voted for the shadow cabinet, and only one woman was elected – Jo Richardson – who was our women’s spokesperson. We argued for there to be a minimum of four women in the shadow cabinet and, to minimise parliamentary Labour party opposition, extra places were to be added. Despite there being no fewer places for men, the change was bitterly contested and called “the tarts’ charter”. But at the insistence of our then leader, Neil Kinnock, the move was pushed through the PLP and more women joined the shadow cabinet.

By 1997, we had a fully formed woman-friendly policy agenda, 100 women candidates in seats we were set to win, and women in the shadow cabinet ready to take their place in the cabinet. This had taken more than 20 years to achieve – but it was a massive change.

Most of the women in the PLP were new, having been elected for the first time in 1997. The senior echelons of the party and the government were still male, as were the top civil servants and the political advisers. But as the women Labour MPs of 1997 gained experience, they became junior ministers and then cabinet members and more women were appointed as special advisers and to the senior ranks of the civil service. And as that happened, our agenda for change for women gathered pace.

By the time we left office in 2010, government had transformed the support for women in their work and family lives. We had introduced children’s centres in every community and more than doubled the number of nursery places. We doubled maternity pay and leave and introduced paternity pay and leave for the first time.

We brought in a right to request flexible working and strengthened protection for part-time workers. We increased support for carers of elderly and disabled relatives. We brought in new laws on domestic violence and strengthened victim support. We brought in a national minimum wage – the biggest increase in women’s pay since the Equal Pay Act of 1975. We topped up the income of low-paid women with tax credits and introduced a minimum income guarantee for pensioners. And we laid the basis for further progress with the 2010 Equality Act.

Today we have a female prime minister but she does not lead for progress in the lives of women in this country. That role, as ever, falls to the Labour party, to our 100 Labour women MPs, our strong network of women councillors and party members, and we will not shrink from that task.

• Harriet Harman MP has written a contribution for the new Fabian Society book This Woman Can: 1997, women and Labour which is published today