On a freezing, rainswept Sunday in a conference room in Birmingham Central mosque, a young woman in a black padded jacket is crying quietly. Her name is Zaynab and as she lifts up her glasses to rub at her eyes, one of the three religious scholars sitting opposite her starts to speak.

“The panel is in agreement, this marriage is to be dissolved today, Zaynab,” says Dr Amra Bone, one of the only female sharia council judges in the country. “It doesn’t have the ingredients of an Islamic marriage; there is no love, trust, compassion or respect. You have an iddah [waiting] period of three menstrual cycles and you are then free to marry again.”

As Zaynab collects her paperwork, Bone’s colleague, Shaykh Talha Bukhari, an elderly man with a white beard, turns to me. “Marriage is not for shedding tears,” he says quietly, “but here they are rolling down.”

I am at the mosque’s sharia council, which in the past year has dealt with 400 requests for divorce. Sharia councils – often mislabelled as sharia courts – have a sinister reputation in the UK. Like halal meat and the niqab, they are a dog whistle for those seeking to imply that there is a creeping Islamification of the UK. In part, this is because sharia – Islamic – law is synonymous in many people’s minds with terrifying punishments such as stoning. The reality of the councils is much less bloodthirsty but there are still reasons to worry.

Almost all the sharia councils, which first appeared in the UK in the 1980s, were founded to facilitate Islamic divorces for Muslim women who need a religious scholar to end their marriage where their husbands don’t consent (they may also offer religious advice on inheritance, wills or issue religious rulings). They are not the only religious councils – there are also the Jewish Orthodox Beth Din, and Catholic tribunals. The sharia councils are often accused of operating a “parallel legal system” in the UK, but their rulings have no legal standing here or abroad, and they have no enforcement powers. As unofficial bodies, they also have no jurisdiction over custody or financial issues. What they rely on is the weight that religious rulings carry in the Muslim community.

Surprisingly little is known about the councils – even down to how many there are in the UK (estimates range from 30 to 80). Some, like Birmingham’s, are large and long established; others are informal, backroom affairs. Individual imams also carry out the same functions, complicating their definition. Samia Bano, a senior lecturer in law at Soas University of London who has written a book on sharia councils, jokes that they are so informal “I could open one tomorrow”. Since cuts to legal aid made civil divorces more expensive, more couples than ever are turning to them. Yet their critics say they pose a serious threat to Muslim women in the UK.

Prompted by fears that they were discriminatory, Theresa May launched a government inquiry in May last year. Just a month later, the Home Affairs Committee announced its own. In December, the Casey Review by Dame Louise Casey into integration included claims that sharia councils “supported the values of extremists, condoned wife-beating, ignored marital rape and allowed forced marriages”. And in January, a bill aimed at sharia councils put forward by the independent peer Baroness Cox (to bring equality legislation to bear on arbitration and mediation services) had its second reading in the House of Lords, six years after she first began lobbying for one.

Birmingham Central mosque. Photograph: David Sillitoe/The Guardian

Women’s groups, meanwhile, have been raising the alarm for some years. Southall Black Sisters, which addresses the needs of BAME women, calls the councils patriarchal and regressive and wants them shut down. Women are being pressured to return to abusive husbands, it says, and they interfere with child custody and financial matters. Muslim women’s groups accuse Sharia councils of ignoring women’s rights under Islamic, as well as civil, law and cite hair-raising cases of women being told to endure marital rape and polygamy. The Muslim Women’s Network points to an instance where a woman was being repeatedly raped by her husband, who had also married again, but was told to be “patient” by a mediator from a sharia council. They say the councils should be reformed, until an alternative way of seeking a religious divorce can be found.

Unsurprisingly, given their negative press, sharia councils are wary of media interest. Birmingham is confident enough about its reputation to be an exception.

Saba Butt is the council’s administrator. In the months before today’s panel meeting, she has collected testimony and paperwork from the spouses involved in each case, starting with the wives. The women are asked if they want to go through a reconciliation process, or straight to the panel for a decision (the councils offer couples mediation). Islamic marriages are contracts (nikahs), signed by both parties and two witnesses. Each must contain an amount of money (mahr) that is granted to the wife. While both men and women can obtain a divorce in Islam, the process is simpler for men (unless the woman has included an equal right to divorce in the contract, and few do).

Subject to various conditions and restrictions, husbands can end the marriage simply by declaring they are divorcing their wife – known as a talaq. A wife can also initiate a divorce (known as a khula), and if the husband agrees, the marriage can be ended. If he contests it, a third party can dissolve the contract – which is where sharia councils step in. Without the council rulings, the panel tell me, many women feel they are still married in the sight of God – even if they have had a civil divorce.

During the afternoon, I watch women file in, one by one, as seven cases are heard. Some are alone, others have relatives with them; some are mothers. There is a teaching assistant and an eye specialist among them, and most hearings are in English (two women prefer to speak in Urdu). All but one have their marriages dissolved.

Zaynab is a young mother. She explains that her marriage fell apart in 2014, and the last time she saw her husband was when he tried to drunkenly break into her home. He has since moved away.

The three scholars question her gently. Is her marriage registered under English law? No, her husband was worried it would affect his benefits. Did he support her and their children financially? Never. Did he have problems with addiction and gambling? Yes. They shake their heads.

A Muslim wedding. Photograph: Photofusion/REX/Shutterstock

Bone says that the panel all work as volunteers and feel it is their Islamic duty to help the community resolve conflicts. Bukhari recites a story of how the prophet Muhammad ended a woman’s marriage because “she did not like being with her husband”.

“A marriage is not for suffering or for sacrifice,” he says.

Yet because each council operates alone, with rulings based on its panel’s personal knowledge and interpretation of religious laws, their approach and decisions can vary wildly. Bano says some of the 25 women she interviewed for her book found sharia councils patriarchal and problematic. Often women got round this by “forum shopping” for a council that suited them. Yet when things go wrong, there is no accountability.

Amara, a 45-year-old lawyer from London, went to see a sharia council in her 20s. During her three-year marriage, she says her husband hit her, tried to push her down the stairs when she was pregnant, and kept her prisoner for three days. She took out an injunction against him, began civil divorce proceedings, and finally approached a sharia council.

Her voice shakes as she remembers how the three panel judges – all elderly men – reacted. “They asked things like: ‘What did you do to provoke him?’” Her husband had been restricted by the court to supervised contact with their children because of his violence, yet the judges insisted on talking about access. “All they cared about was his relationship with the children – not their safety, or my safety.”

Amara dropped the case, but later approached the Muslim College in Ealing. This, she says, “was a completely different experience”. Her case was dealt with in writing, professionally, and resolved within a few months.

One pressing problem is the increasing number of Muslim couples who are at the mercy of sharia councils because they have had religious ceremonies to mark their marriage but are not legally married under UK law. There is no central registry of Islamic marriages (marriages do not have to take place in a mosque, and you do not need an imam), so it is impossible to know how many couples have had only religious services – Aina Khan, a lawyer and campaigner, has estimated that there could be 100,000 couples in Britain (under the current Marriage Act, only Anglicans, Quakers and Jews are obliged to register their marriage).

“In the past five years there has been a steep increase [in couples having only religious marriages]. It used to be about half [of my clients], now it has crept up to 80%,” says Khan. Some couples intend to have a civil service at a later date, others do not realise an Islamic marriage undertaken in the UK is not legally recognised; some feel it is only a religious marriage that is important to them.

Khan says she has also seen an increase in men wanting to avoid losing money or property in a divorce. “Instead of a prenuptial agreement, men are refusing a legal marriage. Women are worried about losing their rishta [marriage proposal] so they say: ‘OK’.” Yet this means these Muslim women do not have legal protection, even if they have given up work to look after children. Women risk being turned out of their homes with nothing if their marriages break down – the Casey Review explains that this can be particularly worrying with the “lower levels of female employment, lower levels of English language and, anecdotally at least, a lack of awareness of other civil rights” in Muslim communities.

“Religion inherently discriminates against women” … Pragna Patel, chair of Southall Black Sisters. Photograph: Southall Black Sisters

Muslim women who have civil marriages will need a civil divorce too. But those with no civil marriage have to turn to sharia councils and risk being left in limbo for years. Khan says one of her clients had started a new relationship and was pregnant with a child with still no sign of her Islamic divorce from the sharia council she applied to.

Khan fears councils are becoming increasingly misogynistic and inefficient. “Sadly they have become a victim of their own success – they are overworked. The Salafi [ultra-conservative] influence on religion has brought in a real misogyny. They have become more hardline and anti-female.”

This can be seen in the most frightening complaint against sharia councils – that with divorce permissible but discouraged by Islam, women are pressured into mediation with violent partners – or even reconciliation. Savin Bapir-Tarvey, a psychologist with the Iranian and Kurdish Women’s Rights Organisation (IKWRO), sees around 15 clients a week, many of whom are extremely vulnerable. She says cultural concepts such as honour are used to manipulate women. “They have experienced severe abuse and their children have witnessed it,” she says, but they are told that “to leave would bring shame on the family”.

Even marital rape can be ignored. “Women who have been through FGM might not make that clear [to their new husbands], but they might say they don’t want to have sex. One woman was told it was her duty – and she should pray while her husband has sex with her – basically while he raped her.”

Bone is clear on the subject of domestic violence: “The Islamic fundamental of marriage is that a woman should feel safe.” If there was violence, “we would go straight ahead and dissolve it”. She also disputes another criticism – that a woman’s testimony at a sharia council is given half the weight of a man’s, insisting that this is not true in her council and is a misinterpretation of sharia law in general.

Over at the well known Islamic Cultural Centre and London Central mosque in Regent’s Park, director Ahmad al-Dubayan is trying to reform councils from within. It has set up a board of sharia councils – 18 so far – with a code of conduct. Dubayan tells me he would like to see less expensive, fairer charges for Islamic divorces (some women pay £400, men considerably less) and an end to delays. He says many Muslims do not understand their marriage rights under Islamic law and that they are putting together a manual to rectify this. There are certainly good experiences amid the horror stories. Khatija from the East Midlands tells me that when she was pregnant with her second child in 2003, she began civil divorce proceedings for coercive control, but her husband defended it. “At that point, coercive control was not a separate offence [in English law]. The judge was appalling. He told me I didn’t seem to have enough reason for a divorce.” Khatija was told to wait until the pair had been separated for five years – which took until 2009.

It was the sharia council in Dewsbury, she says, who took the abuse seriously, arranging an Islamic divorce in a matter of months. “The imam I dealt with was very, very kind. I explained how I wasn’t allowed out of the house, even when I was with my parents in the UK [her husband lived abroad] – he would still control me. Before I went out, I would have to ring to check with him.”

Southall Black Sisters, however, is firm in its opposition. Religion and family law are too dangerous a mix to allow sharia councils to continue to operate. “Religion inherently discriminates against women,” stresses director Pragna Patel. “You cannot access justice if the people who are violating your rights are dispensing it.”

Along with other secular women’s groups, it has boycotted the government inquiry, pointing out that it is headed by a theologian rather than a judge, and has Islamic scholars in place of human rights experts. Sharia council supporters point out that women choose to have Islamic divorces of their own free will yet Patel says this ignores the fact that they do so to avoid being “treated as outcasts” by conservative communities, who view divorce as shameful.

Bano agrees that state law, however imperfect, “is the only system that Muslim and vulnerable women have for protection” and “in family law matters or in issues of vulnerability and marginalisation we should never have a delegation into the community”.

IKWRO is considering another way to take on sharia councils. They are looking for a test case to prove that “marital captivity” – refusing to give a woman a religious divorce – is a form of forced marriage. If men were fearful of being prosecuted under this legislation, the group says, there would be no need for sharia councils.

Yet Muslim women’s groups argue that women who feel they need a religious divorce should not be left without an avenue to obtain one, while Khan says changing the Marriage Act to ensure all marriages are registered would help protect women. A clause in the Islamic marriage contract could then make civil divorces valid Islamically.

Alongside this, she suggests ensuring there are more female sharia judges, and making councils more accountable with a central governing body to ensure all decisions comply with British law. “As a community we should be a beacon on how to have a happy family life, and how to end a marriage in dignity if it goes wrong,” she says.

For the women at Birmingham sharia council, at least, the day has brought some relief. It’s dark outside when the last applicant is told her marriage is dissolved, and she will soon be free to marry again. “That’s the last thing on my mind,” she says quickly.

Some names have been changed