Image copyright Getty Images Image caption Can Labour reconnect with traditional, socially conservative voters?

A new organisation is being launched by a group of Labour MPs - Catholics for Labour.

Mike Kane, the shadow schools minister, will be the organiser of a group to be established at Labour's conference later this month.

So is Labour going to "do God" again? Or is it trying to reconnect with some of its traditional working class, socially conservative supporters?

The group will publish a letter this weekend setting out its purpose - signed by eight other Catholic MPs on the Labour benches, with the expectation of gathering support from the wider party membership.

"We are not about standing still or merely making observations of the world around us. Our hearts and minds are firmly focused on social justice."

But this will be seen as an attempt to make space within Labour for views beyond metropolitan liberalism.

Broad church

Mr Kane had to see off a UKIP challenge to win his working class constituency in the north west. His backing for a Catholics for Labour group represents a different strand from "identity politics" focused on sexuality, race and gender.

He says there are 3.8 million Catholic voters in England and Wales and "Labour will ignore them at its peril",

Image copyright UK Parliament Image caption Mike Kane is the MP organising a group representing Catholics within Labour

The move follows the efforts of so-called Blue Labour, which wanted to re-align Labour away from freewheeling neo-liberal economics and back to an emphasis on families, communities and self-help.

It's much more from the Co-op than the campus.

There is also an underlying concern that liberalism is itself becoming a constricting orthodoxy, so much so that MPs or would-be candidates do not feel able to assert their own religious beliefs.

This is a call that the modern Left should not be intolerant of anything that does not look and sound like itself.

But it's unlikely to be plain sailing.

Gay marriage

When the group is launched, it will want to talk about social justice. But it's much more likely to face tricky questions on same-sex marriage and abortion and whether Catholic values and progressive politics are compatible.

It will also raise wider questions about the place of faith in politics.

Conservative MP Jacob Rees-Mogg set out his religious beliefs earlier this month - and divided opinion over whether this made him more "authentic" or out-of-touch with modern social values.

Former Lib Dem leader Tim Farron stood down because he felt he could not reconcile his role as party leader with his own religious beliefs.

Image copyright Getty Images Image caption How does the modern Labour party view the role of religion?

Labour has often been described as "owing more to Methodism than Marxism". But is the modern Left now culturally hostile to the idea of religion in public life?

Catholics have been among Labour's most reliable supporters.

An analysis by Ben Clements from the University of Leicester showed that in almost every election since the 1950s, Labour had a clear advantage among Catholic voters.

It was support that Labour was once keen not to antagonise.

When Alan Johnson was education secretary he performed what became known as the "fastest U-turn in British political history" when he announced and rapidly un-announced restrictions on Catholic schools.

Declining vote

But Labour's hold on Catholic voters has weakened.

In Scotland, Labour once claimed 80% of the Catholic vote, but this has more than halved, with the SNP taking the spoils.

Across Britain, a 40 percentage point gap between support for Labour and the Conservatives in the 1990s has shrunk to a two percentage point lead for Labour among Catholics voting at the last election.

Image copyright Getty Images Image caption St Andrew's Cathedral in Glasgow: Labour has lost many of its Catholic voters

Of course the Catholic population has also changed across that time, becoming increasingly middle class.

And it includes a wide spectrum of views on both religion and politics - with many Catholics not necessarily agreeing with their own church leaders.

But are some traditionally left-leaning, but socially conservative, voters feeling that Labour is out of the touch with them?

The EU referendum and the defeat of Hillary Clinton last year was seen by some as an indication of how quickly a metropolitan, socially liberal political operation can become detached from the instincts and values of blue collar voters.

Political identity

It's also part of a wider question of identity for political parties that no longer fit their historic labels.

More than three-quarters of Labour members are now in the more affluent ABC1 social classes. In the general election, Labour won many more graduate votes than the Conservatives.

It's the political equivalent of gentrification in housing in London's Labour heartlands. The streets that were once working class now have different occupants with different values.

Is there room for a Catholics for Labour group in the new Left?

"I've always seen my politics as inextricably tied to my faith and I truly believe there is a natural connection between Catholicism and the Labour movement," says Mr Kane.

"My desire to help those who have fallen on hard times all stems from my Catholic upbringing."

But he's also fighting for a piece of Labour's soul - and pushing back against the idea that traditional religious values are becoming incompatible with the modern left.