Labour has pledged to compensate nearly 4 million women who lost out on thousands of pounds when the state pension age was increased.

John McDonnell, the shadow chancellor, said the payments – estimated to total £58bn over five years – would settle a “historical debt of honour”.

Individual payouts to women born in the Fifties could be as high as £31,300, with an average of £15,380.

It follows a lengthy campaign by the so-called “Waspi women” who said they were given insufficient time to prepare for the changes brought in by the former coalition government.

Campaigners and polling experts told The Independent that those bearing the brunt of the overhaul could have a substantial impact on the outcome of the 12 December election.

Forgotten Women: The ordinary lives of extraordinary people Show all 13 1 /13 Forgotten Women: The ordinary lives of extraordinary people Forgotten Women: The ordinary lives of extraordinary people Raped during the Kosovo war, a woman's life 20 years on Sihana was in a house full of women and children when she was raped by a member of the Serbian paramilitary. The men took five of the younger women into separate rooms; one of them had given birth just four days before. “They raped us until they’d had enough. The children were screaming, the old women were screaming, we were screaming,” Sihana says. The Kosovo war ended 20 years ago, but its effects are all too present for this young nation. Approximately 20,000 women and girls were raped during the 14-month conflict; thousands of people remain missing – both Albanian and Serbian – with multiple mass graves uncovered over the last two decades. Tom Ford Forgotten Women: The ordinary lives of extraordinary people How a child bride left her abusive husband in the nation with the highest rate of underage marriage Hadiza was walking home from school one day when people started calling out: “The young bride! The young bride!” The 14-year-old had no idea who they were talking about, and kept on walking. She returned home to find her mother crying but when Hadiza asked her sisters why their mother was so upset, no one answered. This would be the start of Hadiza’s new life as a child bride. Every year 12 million girls are married before they turn 18. Niger has the highest prevalence of child brides, with 76 per cent of girls married by 18, and 28 per cent by 15 in the West African nation. In some regions, girls as young as 10 are married, and after the age of 25, very few women remain unmarried. Tom Ford Forgotten Women: The ordinary lives of extraordinary people How women get into the sex industry - and how they get out of it Rachel Lloyd was forced to leave her school in England after her abusive, alcoholic stepfather drained her mother’s finances then left the family. As an underage teen she was raped by an adult and battled with substance abuse. After moving to Germany, her boyfriend – who was a crack addict – eventually became her pimp. This is by no means an isolated tale. Studies show anywhere from 50 to 90 per cent of women who end up in the sex industry were sexually abused as children. Poverty is another driving force that sees women turn to prostitution. Although some people may choose to work in the sex industry, many are forced into it by circumstance. Tom Ford Forgotten Women: The ordinary lives of extraordinary people How one woman escaped FGM and saved thousands more from the cut When she was eight, Nice Nailantei Leng’ete ran away to avoid being cut. Along with her elder sister, she left her home in the early hours of the morning and hid. When their uncles found the girls, they beat them. “When I was hiding in the trees I was thinking: 'Will they find me and force me to go through FGM? I saw death because of circumcision and I was worried that I might die, or if I did not die I would not be able to go back to school and I would be married.'” Nice is from a Maasai community in Kilmana, Kenya, a nation where the practice has been prevalent for centuries. Tom Ford Forgotten Women: The ordinary lives of extraordinary people Displaced women in Syria are fighting for change Seven years into a civil war that has left devastation in its wake, campaigns and aid are beginning to dry up in Syria. The suffering of those still facing untold hardships is fading from public view as the world moves on to the latest crisis. Thousands are still displaced, living with limited access to basic necessities such as food, electricity and fuel. Unknown numbers are detained or missing. Many of those left behind are women doing what they can to support their families, often mourning the loss of loved ones. Even though there are fewer battlefields, fighting continues, leaving civilians in mortal danger. The message from women in Syria rings clear: “I want you to feel our suffering.” Tom Ford Forgotten Women: The ordinary lives of extraordinary people A woman's tale of gun violence and domestic abuse Gun violence in the United States has become so destructive and all-encompassing, Amnesty International have branded it a human rights crisis. Despite 80 per cent of all gun deaths in the world taking place in America and 30,000 adults and children dying every year in the nation, Congress has done little in recent years. With gun control a divisive issue that some fear to touch due to voter backlash and the right to bear arms enshrined in the second amendment, the government has been quiet. Zero gun control laws have been passed in Congress in the last three years. Tom Ford Forgotten Women: The ordinary lives of extraordinary people The sisters fighting religious extremism in Pakistan Saba Ismail woke up in her Brooklyn home to a voicemail from her sister, Gulalai. She was calling to say she had been apprehended by Pakistan officials upon landing in Islamabad after a flight from London. The Federal Investigation Agency (FIA) told Gulalai she had been put on an exit control list (ECL) and was going to be immediately detained. “The space is shrinking and closing out spaces for civic voices, voices who are raising for peace,” Gulalai says in the message recorded as she was being detained. Illustration by Tom Ford Forgotten Women: The ordinary lives of extraordinary people The terrifying crisis of North America's murdered and missing indigenous women It is North America’s dark, open secret that native women are far more likely to be raped, and far more likely to be murdered. No justice. That is the constant cry from friends and families of victims as countless cases are left unresolved and ignored. Marita Growing Thunder, a 19-year-old Murdered and Missing Indigenous Women (MMIW) activist from Montana, has experienced this lack of justice – five times. Tom Ford Forgotten Women: The ordinary lives of extraordinary people Why violence in Zimbabwe is more than just political As with so many other countries, women and girls are constant targets for violence in Zimbabwe. Data from Zimbabwe National Statistics Office indicates sexual assault is on the rise. From 2010 to 2016 there was a 42 per cent increase in rape cases, with at least 21 people raped every day. Taking into account the fact that many don’t report sexual violence, this figure is likely higher. Womankind Worldwide Forgotten Women: The ordinary lives of extraordinary people How Rwanda rose to the top of the world for women's representation The only one of 14 siblings to survive, with four children of her own as well as nieces to look after, Vestine survived the Rwandan genocide. Unique conditions grew from the horror, leading Rwanda to become a female-led African nation. As Vestine says, “Our genocide is not something that can be easily forgotten but we try to live with them and work with fellow citizens for the development of our nation. I can say that Rwanda has tremendously tried to rebuild itself. We remember our loved ones who perished during 1994 genocide against Tutsi as we rebuild ourselves. We have enough security in our nation and we are all working together to rebuild our nation. Specifically, women are rebuilding.” With male bias dominating so many nations, Rwanda shows that not only can a country thrive and grow with proper gender representation, but that it can help a nation heal from the unimaginable. Illustrations by Tom Ford Forgotten Women: The ordinary lives of extraordinary people Why women in South Africa are carrying the burden of HIV South Africa has the biggest HIV epidemic in the world, with 7.1 million people living with the virus. There is a huge gender disparity in infection rates, with nearly four times the number of young women infected than men their age. Not only are women disproportionately infected, but there is another burden tying them to this life-changing illness - childbirth. Many women have been unknowingly infected with HIV, then unknowingly passed it on to their children. Tom Ford Forgotten Women: The ordinary lives of extraordinary people One Syrian mother's remarkable journey to find her son More than 500,000 people have died since the Syrian conflict began in 2011. With thousands of men imprisoned or killed at the hands of Isis and the Syrian army, many women are left behind fighting for survival, without even the solace of knowing whether their husbands and sons are dead or alive. Tom Ford Forgotten Women: The ordinary lives of extraordinary people The fight against brutal land grabs in Uganda A 30-year-old mother with six children, Patience is doing everything she can to rebuild her life. Her husband, Isaac, died four years ago in a Ugandan land grab, which saw her family forcefully evicted so a sugar factory could be built on the land. “One day, we were at home and we heard screams. There was so much violence. Guns, teargas and machetes. If you delayed they burned down your house. I heard screams everywhere and I started running. They took our goats, cows, chickens and our whole home.” WomanKind Worldwide

Boris Johnson was challenged about the issue by a woman in the studio audience for Friday night’s BBC Question Time election special, but said he could not promise to “magic up that money”.

However, on Saturday night Mr McDonnell announced that Labour had “prepared a scheme to compensate these women for a historical wrong”.

“It’s one that they were not able to prepare for and for which they’ve had to suffer serious financial consequences for as a result,” he said.

“Some of them have been hit by a combination of poverty and stress, having lost out on what they had contributed towards.

“These changes were imposed upon them by a Tory-led government. So we have a historical debt of honour to them and when we go into government we are going to fulfil that debt.”

Last month the High Court ruled against women who argued that the rise in the pension age for women from 60 to 66 “unlawfully discriminated against them on the grounds of age, sex, and age and sex combined”.

Conservative minister Michael Gove said Mr McDonnell's promise had "driven a coach and horses" through Labour's claims to have a fully costed programme for government.

Mr Gove told BBC1's Andrew Marr Show the Conservatives were "naturally sympathetic" to the position of the Waspi women.

"We provided additional funding in order to smooth the transition which previous governments have acknowledged needs to be made when we're equalising the pension age," he said.

"One of the problems of course with Labour's position is that they are spending money which they pledged not to spend. When they launched their manifesto earlier this week, they said that they would have certain rules about spending and they wouldn't borrow beyond a particular limit.

"They've now driven a coach and horses through those rules, and they are planning to borrow and planning to raise taxes in a way which will cause further damage to our economy."

The director of the economic thinktank the Institute for Fiscal Studies, Paul Johnson, said that the offer drove "a cart and horses" through Labour's promise not to borrow for day-to day spending and committed the party to £12 billion of additional borrowing for the next five years.

"It is a very large amount of money so there's a real issue about priorities here," Mr Johnson told Marr. "Labour are prioritising this group of women, some of whom feel very unfairly done by, but they're not, for example, prioritising working-age people who have seen their benefits cut over the last four years and have had no increase for inflation.

"That's several hundred pounds loss for some very poor people of working age with children who got no warning of that either. And while some of these women clearly have had a hard time, the majority are actually much better off than those working-age people who've lost out."

Liberal Democrat leader Jo Swinson said her party would wait for the conclusion of an ongoing investigation into the issue and "respect what the Ombudsman comes up with".

Responding to Mr McDonnell's offer, she said: "I don't think it's helpful to anybody to put forward uncosted pledges. Where's the money coming from? Anybody can write a wish list and say all of these wonderful things that people could have, but I think people generally know that you don't get something for nothing."