When asked who she was referring to, Dame Margaret said: “The leader’s office is the usual shorthand.”
Earlier, she said the block to Labour moving to a Remain position was not Mr Corbyn himself.
She said: “I don’t get the impression that it is Jeremy himself who is the stumbling block.
“I think there are people very close to him, with great influence with him, who are and have been from the beginning passionately opposed…
“He wants to keep the party together as much as possible and present a united front on the issue.”
