BOB Spink MP does not intend to resign and put his case to Castle Point voters in a by-election, although he is clearly a very different politician from the man they elected in 2005.

Since then, he has frequently defied and ultimately resigned his party whip.

Now in a final split from the Tories, he has defected to the UK Independence Party to become its first ever MP.

Mr Spink sees this as a principled move, consistent with his political convictions. But high principles cut both ways.

He has moved so far away from the manifesto on which he was put into Parliament that any last vestigial excuse for not putting himself up for re-election has been stripped away.

UKIP represents a slender constituency. Its single issue obsession is out of touch with mainstream concerns.

The electorate places crime, health, and the economy far higher than Europe as significant issues. The number of Castle Point voters who voted UKIP in 2005 was small.

Certainly Mr Spink enjoys popularity in Castle Point, but it is asking too much of voters to presume their support for the full extent of his volatile activities or his move away from the centre ground.

Besides, if he really believes his every move has the full support of voters, then he should have the guts to put this belief to the test in a by-election.

As it is, he looks less like a lone hero of politics than a rootless maverick at the mercy of a political tempest of his own making.