Does that mean that the local candidate can count on his support, then? He looks down at his feet. "Er, well I've got a bit of a problem with my address at the moment."
It transpires that Mr Goldsmith - this is James Goldsmith the homeless man from Gravesend, of course - hasn't got one, but he can be contacted via his mobile phone.
Labour's overseas aid spokeswoman hoots with laughter. "You're of no fixed abode and you've got a mobile phone? You are nineties man!"
With or without his vote, Mr Goldsmith is sure the Conservatives' internal battles will finish them off.
"Absolutely," Ms Short agrees. "And we are completely united." There is no obvious irony in her words. She may have been unhappy about the way New Labour was run in the past, but there is not a hint of it today.
Out "on the stump" with Chris Pond, director of the Low Pay Unit and Labour candidate for Gravesham, she is loyal to a 't.'
Gordon Brown's plans for more privatisation? She is all for them.
"We have always believed in a mixed economy. People like me have never said extending the public sector was Socialism," she says, stoutly.
The mood is convivial as the small carnival weaves through the thin Monday morning crowds, here offering handshakes, there accepting a hug or a kiss on the cheek.
One very plummy lady rushes up to tell Ms Short she thinks she is "absolutely super."
"I've seen you lots of times on the television," she gushes. "I hope you get an absolutely wonderful job in the government."
Such enthusiasm has to be admired. Already a healthy handful of Labour front-benchers and an equivalent number of Conservatives have glad-handed their way through here, along with a quite staggering number of soap opera characters.
EastEnders stars go down especially well, for Gravesend was the fictional destination of Dot Cotton when she took leave of Albert Square. Michael Cashman caused quite a stir, as did Leonard Fenton, who plays Dr Legg in the series. And the local police were thrilled to be introduced to Simon Rouse, DCI Meadows in The Bill.
There must be Tories in the town - its Conservative MP had a majority of 4,500 at the last election - but few can be found this morning.
Perhaps the New Labour machine is so efficient that it has managed to sweep the opposition off the streets. Even the three "nurses" who began the day wrapped in red tape for a photo-call turn out to be a Labour Party researcher, a full-time party volunteer and someone who works for the Low Pay Unit.
Down at the campaign headquarters, they are busy stuffing envelopes: personalised letters with different messages for Tory faithfuls, waverers and long-term Labour supporters. The talk appears to be in code.
Squeezers, explains Maureen Pilcher, the office manager, are Liberal Democrats who might be persuaded to vote Labour. Switchers are former Tories.
"And," she adds solemnly, "I believe the twitchers I keep talking about are some kind of bird-watchers."