Thatcher never for one moment seriously considered handing over to anyone. Would we not go on and on? It was entirely consistent with this for her to allow it to be thought that the weak and malleable John Major was her heir apparent and so in effect have no heir apparent.
It took the near-universal recognition that she was barking to render her fallible. No one won the resulting leadership contest: she had already lost it. Major, minus his wisdom tooth, was awarded the prize for causing least offence to most Tory MPs and won the following general election for not being Thatcher. He then lost the next one for being himself and for the Tories being Tory.
Bury St Edmunds, Suffolk