The biggest surprise when it comes to the ongoing national debate about immigration is that it has taken this long to arrive. The Windrush scandal has raised questions over the government's 'hostile environment' policy towards illegal migrants, the immigration targets and the wider way in which people are treated by the Home Office. The controversial decision of the BBC to mark the 50th anniversary of Enoch Powell's 'Rivers of Blood' speech with a special programme, including playing the speech in full, has further raised debate over integration and the rhetoric that surrounds migration policy.

This has been a gross oversight. For one thing, it is an issue which resonates deeply with voters across the political spectrum, and in fact has always rated highly as such since at least the 1950s. For another, Brexit necessarily demands a new migration policy – and provides an opportunity for a bold government to propose something truly radical. It has been a disappointment that that debate has not been provoking many creative ideas thus far.

That critique holds as much for the church as it does for the policy world. Christians, and faith groups more broadly, have been leaders in providing services and protesting the government's policies on refugees and asylum seekers. However, that group makes up only around three per cent of migrants. On the other 97 per cent, and the future approach the UK will take, the church has been quiet, even passive. This is despite the fact that this is an issue of both enormous public concern and one in which there are significant potential theological and ethical resources to be brought to bear.

This was why we at the Christian think tank Theos set out to commission a collection of essays that would try and put creative ethical approaches to migration back on the agenda. In Fortress Britain? Ethical Approaches to Immigration Policy for a Post-Brexit Britain we asked a group of predominantly (though not exclusively) Christian thinkers to answer the question of what a new ethical approach to migration might look like.

Inevitably such an approach provokes difficulties. Christian thinkers do not necessarily agree with one another on the issues that cluster around this question, such as the kinds of rights to be accorded to future migrants, the related issue of what responsibilities are required of migrants to attain citizenship, and even the extent to which engagement with outsiders is an important and healthy aspect of what it means to be human. These differences highlight how hard it is going to be to resolve the current debate. However, they also highlight how much ethical reflection and Christian theology have to offer in a debate on which the church has too often stood on the sidelines.

The Church has done wonderful work in the refugee and asylum sectors, but the Windrush scandal brings into sharp relief the fact that it is not only the most vulnerable who demand some sort of ethical response. The treatment of any immigrant is an ethical issue, particularly if the policies enacted lead to negative consequences for those immigrants. We need a new ethical conversation on the future of migration policy as a whole.

Ben Ryan is a researcher at the Christian think tank Theos and editor of 'Fortress Britain? Ethical Approaches to Immigration Policy for a Post-Brexit Britain'. Follow him on Twitter @BenedictWRyan