For Labour supporters used to hearing the party's mantra of "no complacency" Ms Short offers a rather refreshing vision. There is, she argues, an historic shift in the voting patterns of women which "could explain a Labour domination of the next 50 years".
Over tea in her cramped Westminster office, she expanded the argument: "All over the world women's votes are moving. They're moving towards more progressive parties. Clinton is in power because women stayed with him and moved to him. It increases with women's participation in the labour market. We're talking here about historical change, not just one election ... a historical shift in voting behaviour which will help not just to bring Labour into government once, but to sustain it in power."
This is not a thesis you will hear advanced from a Labour leadership nervous at the very hint of a landslide let alone a 50-year Reich. And it is one example of why, despite her undoubted popularity with voters, Ms Short has yet to appear at an early morning press conference. By general consensus she is a little too honest for her own good and cannot be completely relied upon to stay "on message".
She has, however, been on regional tours and they have given one of Labour's best-known politicians a different perspective by standing back from the election campaign. As with sport, she says: "People who watch the game sometimes see more of it. I try to see more of what's really going on than the people in the hurly-burly."
She argues: "Two elections are taking place. There's a media election and there's a real-people election and when you go on the sorts of visits I go on, people come up and say, 'Clare, are we going to win this time?' The elite that run the top of the political parties and the media are in a different country, in a different game in a different politics and that's quite boring."
This is sensitive territory, after her criticism last year of "the people who live in the dark" - the party's spin doctors. Within weeks of the election, Ms Short is anxious not to rock that boat. She is, she stresses, not criticising anyone in the Labour Party for playing the game they have to play.
But she is sad, she says, at the state of political discussion in Britain. She singles out the "yah boo culture" of Question Time in the House of Commons which she believes has deteriorated even in the last five years. "You sit there and think they really ought to come in with silk dressing gowns because that's what it's like: 'Yeahhhh' and 'Aghhh'. I've reached the stage where I find it frankly embarrassing to sit there and I think it's a good job my granny isn't here."
Women will be crucial to changing the culture. The 1992 election returned to the Commons more men with the first name John than women. Though Labour has now abandoned positive discrimination in favour of women candidates, up to 100 women Labour MPs may be elected on 1 May.
Ms Short believes women and men have the same political agenda, but that women voters see that agenda more in terms of individuals than abstractions. So is Labour doing enough to woo women? "Me? I think I am. I hope so." And Mr Blair? "I'm sure," she says with a diplomatic chuckle, "he must be doing very well."
The other agent of change could be proportional representation, a policy over which Mr Blair is notably cautious. Labour is committed to a referendum, but not to backing any change in the voting system (although Ms Short "wouldn't be surprised" if Mr Blair came round to backing electoral reform).
Ms Short still feels bruised by her sacking last year from the post of transport spokeswomen (she was, she says, "deliberately publicly humiliated"). But she enjoys her new brief of overseas development and has won a manifesto commitment that it will have a Cabinet rank in a Labour government: "To have it as a tokenistic kind of 'charitable aid giving to the impoverished of the world' department would not be adequate. I would like a strong department and I think it's likely I will get it but I don't know for certain." That means a job which would encompass trade and debt.
Throughout an hour-long interview, Ms Short has been pretty diplomatic. But, asked about Labour's new ally, the Sun, with whom she waged a long campaign against page-three girls, she does what voters most like about her, and speaks her mind.
"I want as many newspapers as possible to support the Labour Party, so I'm glad the Sun is supporting Labour. I have criticisms of the fact that they think it's normal and acceptable to carry daily pictures of half-naked women, which is revolting, but I'm still glad they're supporting us."
Nor is she totally impressed by Mr Blair ducking a question about an article by him being placed opposite a page-three girl. "He said, 'I think I'll explain my position on the European Union.' I mean he could have said, 'I don't like it actually but that's where they put it.'"
She also eschews the near-obligatory Labour caution about discussing the Sun's proprietor, Rupert Murdoch: "I assume, given how he is sort of interested in controlling the media in China and India, he'd spend less time on British politics, and I'm rather glad of that fact."
That, at least, marks Ms Short out as a genuine optimist.Reuse content