Can John Major rely on his "nice man next door" persona to woo the electorate? Will Tony Blair inspire voters with his personal charm and fixed smile? Or can Paddy Ashdown persuade the waverers to his cause using the "honest alternative" ticket?
Academic research could offer insights into the characters and leadership potential of those who would be prime minister.
Roger Gill, director of the Research Centre for Leadership Studies set up last month by the Leadership Trust, believes Mr Blair shows the most interesting leadership profile. "He uses reward and punishment - shape up or ship out - to discourage, for instance, non-consistent behaviour within the party," said Professor Gill. "But at the same time he uses inspiration to motivate people, and charisma certainly. He knows how to express commitment to a vision."
This is known as transformational leadership, says Professor Gill. Such individuals typically use intellectual stimulation to influence others. They often use consultation and participation and sometimes show concern for the individual by identifying their unique needs.
By contrast transactional leaders use "management by exception", where individuals are openly punished or rewarded as an example to others. Blair is unusual in employing this trick, as well as the techniques of a transformational leader, according to Professor Gill.
Transactional leaders are invariably directive and not as effective as transformational leaders in Professor Gill's model. "Robert Maxwell was a typical transactional leader, always reacting strongly to mistakes and rewarding those who did his bidding."
Margaret Thatcher on the other hand tended to use inspirational motivation as her main leadership technique. Charisma, colourful language and a strong vision were her trade marks.
So what of Mr Major and Mr Ashdown? "I'm not sure they display enough of either leadership style, which implies they may not be strong leaders," Professor Gill admitted.