Vote Rantzen?

Esther Rantzen has decided to contest Luton South at the next election despite being quoted on the BBC as saying:

"Political experts have told me I would be crazy to stand, that I haven't a hope in hell, that it will lead to humiliation and embarrassment on my part..."

Are these experts right? One of the secondary but intriguing features of recent elections has been the return of "independent" MPs. Since 1945, independents and even small-party MPs have hardly flourished. Yet since 1997 we have seen Martin Bell elected as an independent, Richard Taylor for Health Concern (2001 and 2005), and George Galloway for Respect (2005). Add to this the way the share of the vote for "others" keeps creeping up year on year and the grip of the "big three" parties on Westminster politics looks like it is weakening.

Well, perhaps. Certainly the smaller parties have learned to target their meagre resources and use a presence in local government as a base to challenge for Westminster seats.

But the prospects for genuine independents are much less promising. For each one who has succeeded in recent years, dozens stand and get nowhere. Success depends on a combination of three factors:

1) A strong local issue: the proposed closure of Kidderminster Hospital kick-started Health Concern, while the Iraq War played out strongly in Bow in 2001 and Neil Hamilton's decision to run again in Tatton despite being mired in scandal helped galvanise opposition there.

2) An effective electoral machine: this was crucial for Galloway in 2001, while having local councillors helped Dr Taylor retain Wyre Valley in 2001. And John Sweeney's excellent book on the Tatton election shows how hard it was for Bell's campaign to gain traction, and how critical the influx of supporters (not all with the presence of David Soul) was to building momentum and credibility.

3) A free run: probably the most critical factor is having one or more of the main parties standing aside. Bell and Taylor both gained enormously from this.

Using this score-card, the Rantzen campaign does indeed look doomed. The current MP Margaret Moran has already announced she will not stand again, so MPs' expenses will not have the same local dimension as at Tatton. She has no effective machine in place - no website, for example, to turn the interest surrounding her announcement into support or donations. And there is little prospect of any other party standing aside.

But Ms Rantzen says she is "fascinated by politics", which is reason enough to have a go.