However, as the details of the reshuffle began to emerge, her allies said she had been blindsided by the timing and detail of the announcement, which also overshadowed her delivering a key policy announcement on overhauling the regulation of ministerial standards. 

“I just find it completely bizarre that the deputy leader isn’t aware of the changes being made to the shadow cabinet and hasn’t been consulted,” one senior ally said.

A second supporter of Ms Rayner claimed the controversy had “blown up” an event designed to shine a spotlight on Boris Johnson’s mishandling of the recent sleaze scandal.  “I would be careful if I were him,” a third added.

Ms Rayner also appeared to signal her frustration publicly when fielding questions after her speech, telling reporters: “I don’t know the details of the reshuffle or the timing of it. 

“I’ve been here concentrating on my role now, but six months ago I said again we need some consistency in how we’re approaching things as an opposition.”

Supporters of Sir Keir defend him against claims

However, senior figures loyal to Sir Keir hit back against the latest briefings, insisting that he had informed Ms Rayner at a meeting on Monday morning that the reshuffle would be taking place. 

An aide to one shadow cabinet minister also claimed Ms Rayner had definitely “known about the plans” and had been “pushing for it for months”.

Others singled out members of Ms Rayner’s team, accusing them of personally stoking tensions, while two also hit out at suggestions Ms Rayner had the right to be involved in decisions relating to changes to Sir Keir’s frontbench. 

Elsewhere, Jo Stevens announced she had been shuffled from the shadow culture secretary brief to shadow Wales secretary, while Jonathan Ashworth was moved from health to become the shadow work and pensions secretary.