The political conundrum of right and left

By Andrew Marr BBC political editor

How much does that traditional division between left and right really still matter in British politics?

From Westminster to Brighton, where the Liberal Democrats have been basking in the result of the Brent East by-election, this is turning into one of the more interesting political conundrums of the autumn.

'Watch for the law of unintended consequences'

On Thursday, Charles Kennedy rather airily announced that left and right is Westminster talk. It has no resonance or relevance outside, which of course is highly convenient for him.

His party has 54 seats now, but one obvious problem. It's seen by voters as somewhat to the left of Labour yet three quarters of its target seats are Tory ones in conservative areas.

The Tories, unsurprisingly, are now trying to hammer home the message that Red Kennedy, as they call him, is a raving leftie.

The Liberal Democrats are trying to respond by emphasising their keenness to cut back central government, making savings and generally behave more cautiously on taxing and spending.

A strange rebirth of Liberal England would hit the Tories first, further dividing the opposition side of the Commons, something that would delight New Labour

But the real question is whether, out there, a new constituency is arising which is simply less interested in or knowledgeable about ideology of the left or right variety.

Since there is now a large group of voters fed up with Tony Blair, yet whose social instincts are too liberal to allow them to think of themselves are natural Tories. An ideological people? A Liberal people. And Kennedy repeated the word liberal again and again.

Could something be happening? Well, it's possible abstention and protest are real problems for Labour. Thoughtful Lib Dems say the Tories can't and won't disappear. Every democracy has a centre right party and the Conservative bedrock is somewhere between 25 and 30% of the country.

'Decapitation' strategy

But they do think lack of interest in the Tories, distaste for New Labour and a less ideological generation are combining to shake things up in unpredictable ways.

They're targeting the seats of prominent Tory MPs, in what they call their "decapitation" strategy.

This shaking change in the political landscape could actually help the very government against whom these people are supposed to be revolting

Suddenly this party of amiable vegetarians is sounding carnivorous. Could they be the real winners from a collapse of the presidential style of politics, exemplified by Tony Blair?

If so, watch for the law of unintended consequences. Because in terms of target seats, three quarters of the Liberal Democrats best prospects are Tory ones. The next 20, 30 or 40 seats won would contain relatively few stolen from Tony Blair.

So a strange rebirth of Liberal England would hit the Tories first, further dividing the opposition side of the Commons, something that would delight New Labour.

This shaking change in the political landscape could actually help the very government against whom these people are supposed to be revolting.

Of course, this also means the Lib Dems, being seen as, well, fashionable.

Watching them in Brighton, with those cord jackets still slack with metal badges, some reassuringly bushy beards and anxious youngsters, it's a little hard to think of them as cool. But what do ageing political obsessives from Westminster know about cool?