The recent formation of the All-Party Parliament Group (APPG) on get refusal marks a new phase in efforts to help agunot, women chained to a dead marriage because their husbands deny them a religious divorce, even though their union may have been civilly dissolved. It signals that this is not just an internal problem for the Jewish community but has become something of a national scandal.

This week the APPG hosted the launch of a book designed to further up the pressure on the religious authorities. Daniel Greenberg’s Getting A Get does not mince words and is unsparing in his criticism of batei din.

The Orthodox barrister wants to see an end to “get exploitation” where the religious divorce can be used by a spouse as a bargaining chip to extract a better financial settlement or custody arrangements from their ex. Using the get as a negotiating tool is “an unacceptable corruption of religion and a form of abuse the secular law must deal with if the community regulatory authorities are unable or unwilling to address it,” he writes.

What’s more, he warns that dayanim could end up on the wrong side of the law if they fail to change practices in their courts. In his book, he reveals that last year he came to the aid of a woman whose husband claimed she owed him money and would not give her a get unless she agreed to attend an arbitration at a beth din.

He wrote to the beth din to warn that this could be tantamount to blackmail and the rabbinical court could put itself at risk of being seen to assist this. He did not receive a reply from the beth din but within days the woman received her get.

Rabbinical courts, he argues, should leave issues such as finances and custody of children to the expertise of civil family courts and not interfere. And instead of leaving the resolution of a get until after other matters have been agreed, the rabbis should insist that the get is sorted out first.

It should be made clear, he writes, that “by continuing to allow Jewish ritual to be a tool of oppression of either former spouse by the other, they render themselves unfit to exercise rabbinic authority within the Jewish community”.

He makes a number of recommendations including calling for the creation of a “communal commission” to examine the practices of UK batei din. He also reveals that he used data protection law to help one woman receive confirmation of her divorce from a beth din which had withheld the certificate confirming her get because the bill for the get procedure had been left unpaid.

It is not only over potential blackmail that the rabbis could be exposing themselves to legal challenge, he believes. Statutory guidance to last year’s Domestic Abuse Act, which is due to be published shortly, will for the first time recognise get refusal as a form of “spiritual abuse”. This would make it easier to prosecute a spouse for coercive control or enable a victim to obtain a domestic abuse order from the courts to prohibit certain actions.

For 20 years, civil judges have already had the discretionary power to withhold a secular divorce if one of the parties impedes the other’s right to remarry, for example by refusing a get. More recently, existing coercive control laws have occasionally been used to launch private prosecutions against obstructive husbands. But the new law would considerably strengthen the hand of victims of unreasonable behaviour.

However, the rabbinical authorities have warned that using the secular law could be counterproductive for a woman. If they believed a man were giving the get to avoid risk of prosecution, he could be seen as acting under duress and this would invalidate the get, which must be given freely, according to Jewish law. While there are circumstances where a man can be pressured into giving a get, the prevailing rabbinical view is that the beth din must hear the case first and thus be consulted before the launch of any criminal prosecution in the secular courts.

But if a rabbi were to discourage or inhibit a woman from enabling a prosecution for coercive control, Mr Greenberg believes, he could be at risk of perverting the course of justice under criminal law.

The rabbis’ current stance stems from a ruling in the Mishnah that a secular court cannot impose a get, unless it is acting according to the express wishes of a beth din.

But Mr Greenberg believes the rabbis have it within their means to update the halachah.

The relationship between Jewish and secular courts was different in antiquity and in medieval times, he told the JC. “Today a man who… participates in a secular divorce is clearly intending to end the marriage… So the idea that they haven’t accepted the end of the marriage is just bonkers.”

Furthermore, he argues that since Jewish law forbids forcing someone into a marriage, “halachically it is just as objectionable to force a person to remain in a marriage they no longer want to be in”.

The Torah itself states only that the religious divorce has to be initiated by the man, he explained. “There is nothing in biblical law to suggest that it is intended to give him a substantive veto or a right to extort money.”

And just as bigamy was outlawed in much of the Jewish world over a thousand years ago when rabbis took account of wider social mores, so rabbis now should be prepared to exercise similar creativity in preventing “marital captivity”.

Getting A Get is available from danielgreenberg.co.uk from £5.