Songs of Praise special on Princess Diana to suggest she had more of a Christian faith than was widely believed

Diana, Princess of Wales, had more of a Christian faith than was widely believed, a Songs of Praise special will claim, as it explores the inspiration behind her charity work.

The long-running Sunday afternoon programme is to air a special episode quietly exploring the late Princess' religion next week.

In it, friends will describe how she had "stronger faith than people give her credit for", as they reflect on how her Christian values informed her charity work.

Aled Jones, the presenter, will also recall how he was invited to sing for her personally in her Kensington Palace living room, while the congregation of All Saints Church, Northamptonshire, near her family home of Althorp, sing favourite hymns.

Among the contributors is Mike Whitlam, former director general of the British Red Cross who worked with the princess on charity campaigns including her famous land mine trip to Bosnia.

Saying he had been asked to speak to many outlets about the 20th anniversary, he disclosed he had said yes to Songs of Praise because of its religious focus.

"I think she had a stronger faith than people give her credit for," he said, adding he believed that a form of religious conviction helped her to persevere with her charity work.

"She wanted to put love where there was hatred, and make a huge difference to people's lives so that they could live a better life," he said.

"When you talk to people about making the world a better place, there are not many people who think it's doable. She did."

Tracy Borman, joint chief curator of Historic Royal Palaces, told the programme Diana's compassion and charity work "of course absolutely reflects very Christian values too.”

Due for broadcast next Sunday, it is one of a handful of further documentaries about Diana, Princess of Wales, or involving her sons.

Following an ITV 90-minute special, in which the Duke of Cambridge and Prince Harry shared intimate memories of their mother, the brothers will also contribute to a BBC documentary about the week between her death and funeral.

Also due for broadcast on Sunday 27th, it will see the two princes share their memories of those seven days.

It is understood that the Duke and Prince hope to set out the truth on the 20th anniversary of the Paris car crash, in part for the purpose of correcting the historical record.

ITV is to run a programme on a similar theme, scheduled for Tuesday 29th against the Great British Bake Off on Channel 4 and also set to detail the funeral.

It will not include Diana's sons, but features testimony for those involved in overseeing the extraordinary national mourning.

This week will also see Duke of Cambridge appear on television as part of a Channel 4 documentary starring newsreader Mark Austin and his daughter Maddy, speaking about her anorexia.

Miss Austin ran the London Marathon for Heads Together, the mental health charity spearheaded by the three young Royals, with the Duke expected to emphasise the important of speaking about emotions in his on-screen appearance.

The Songs of Praise special will focus closely on Diana's charity work, interspersed with hymns including I Vow to Thee My Country, which was played at her wedding and funeral.

Songs of Praise - Celebrating Diana, will be broadcast on Sunday, August 27th at 4pm on BBC One.