A portrait of the Prime Minister: what drives Theresa May?

It’s her name on the battle-bus, on the election leaflets and on the placards that surround every speech that Theresa May makes. For the Tories, the Prime Minister is the prime asset of the party in this highly-personalised campaign. But what is it that drives Theresa May herself? Channel 4 News has been speaking to some of those who know her best, including her former Oxford tutorial partner, who remembers her saying in their first term that she wanted to become Prime Minister.