When Rebecca Long-Bailey stood in for Jeremy Corbyn at prime minister’s questions this month it was seen as the clearest sign yet that she was being groomed as heir apparent to the leader.

The 39-year-old shadow business secretary — a protégée of John McDonnell, the shadow chancellor — has been fast-tracked for promotion by Mr Corbyn. She was on Labour’s negotiating team for the cross-party Brexit talks alongside Seumas Milne, the leader’s strategy director, and Sir Keir Starmer, the party’s Brexit spokesman.

The docker’s daughter from Manchester, educated at Chester Catholic High School, began her working life serving at the counter of a pawn shop.

Rebecca Long-Bailey became shadow business secretary in 2017 YUI MOK/PA

It was an experience, she once said, that taught her “more about the struggles of life” than any degree could.