He says he can testify that she “is not preoccupied with the manner of her departure from this world”.

“We never talk about snuffing it when I see her. Apart from being tastelessly morbid, I have too much political excitement to convey to her from that day’s newspapers.”

Baroness Thatcher, 82, would be – other than monarchs – only the ninth person (the fifth prime minister) and first woman to be taken by military procession from lying in state in Westminster Hall to a funeral service at Westminster Abbey or St Paul’s.

Her final journey would be on a gun carriage drawn by sailors.

According to Labour’s deputy leader Harriet Harman, a decision has not yet been made.

Sir Bernard adds: “All this funeral talk just washes over her.

I find that a blessing.

 It also means that the debate about the justification for the honour can proceed as if she wasn’t there, not that she was ever unduly sensitive to criticism.”