An inquiry is not the same as a trial. There is no jury or prosecution and it cannot produce a guilty verdict, but it will attempt to establish where responsibility lies and note any lessons.
She was initially appointed to the newly-created role after departing as Sir Keir Starmer's chief of staff last month,The government had previously said she was taking a short break before starting her new position.
But a No 10 spokeswoman said she had "now decided not to take it up".The news was first reported byThe BBC has been told the PM had decided to withdraw Ms Gray's job offer and that the cabinet secretary, the country's most senior civil servant, had spoken to her to confirm this.
This chain of events is not disputed by other figures in government.But the BBC has been told Ms Gray is adamant it was her decision and she never spoke directly to Sir Keir about it.
A friend of Ms Gray said: "Sue has taken a decision not to take the role. She’s going to focus on other things."
They added: "She's taken time to think about it properly, talking to stakeholders, but ultimately she's decided she doesn't want to do it."The couple have a long history of working for social good: Chris raises money for charity as a singer in the socialist street choir Cor Cochion, while Valerie has been volunteering with Cruse Bereavement Support for 21 years.
Chris said he and his wife were very aware of the acute need for overnight housing in Swansea when they made their decision to donate."They are lovely people and to be doing the work they do is quite amazing," said Valerie of The Wallich.
"Both of us have done a whole load of travelling in our careers, too much really, and so we don't want to do that anymore," she added."We are quite content to just live a quiet life, eat out now and again, and we've got everything we need."