Former chief policy adviser to Margaret Thatcher, John Redwood, described her as "the best boss I ever had".
"We had to work very long hours to keep up with her," he said.
Fighting back tears he said:
The most moving moment inside the cathedral was when they opened up the great doors and we could hear the noise outside.
It was exactly the kind of tribute you would hope for - we are grieving a loss but also commemorating a life well-led, an extraordinarily active life.
Asked about protests, he simply said: "It is a free country."
The Queen led mourners at the ceremonial funeral of Baroness Thatcher in St Paul's Cathedral today as thousands lined the streets of London.
Falklands residents say they owe their freedom and their riches to Margaret Thatcher. Today they paused to reflect and to remember.
Baroness Thatcher was honoured with a ceremonial funeral at St Paul's Cathedral in the presence of the Queen and dignitaries.