SO WHERE are they? The election posters in people’s windows, I mean. I live in a marginal seat and I haven’t seen a single one. I am not alone. Campaign historians believe that there are fewer to be seen this time than there have been for a century.

I used to measure political life by them. They told of the solidity of a Tory suburb, or that the Liberals were about to win a by-election. I remember touring Bermondsey in 1982 and spotting a tower block where Simon Hughes had enough support to have his name spelt out on adjoining windows.

You can date the revival of Labour campaigning to the 1986 Fulham by-election, where window after window endorsed Labour’s local man with the words “Nick Raynsford lives here”. These posters were the early work of Trevor Beattie, who now designs Labour’s national advertising campaign.

With the disappearance of window bills a little bit of our history will be over. It was Charles Geake, the Peter Mandelson of his day as head of the Liberal Publication Department, who devised a strategy for the two 1910 elections of using small posters. In Tony Benn’s diaries his mother is pictured holding a 1910 window poster telling Tory canvassers not to call “as we are all for Benn”.

In the early days posters carried political messages, my favourite being the 1922 Labour campaign to remove the MP J.W. Hills, with the slogan “With faith you can move mountains, with your votes you can remove Hills.” These days they usually carry simply the candidate’s name.

Yet even in their decline window posters speak eloquently about modern politics. The relative paucity of these items tells you a great deal about what is happening in this election on the ground.

First it tells of the decline in party identity. Fewer voters than ever are willing to display party colours in their windows. Some explain this reluctance by arguing that they worry about getting a brick through their window. In fact there have been surprisingly few incidents of this kind reported to the police in modern elections.

The next thing you can learn is that parties no longer have enough activists to staff campaigns properly. Window posters will appear (as opposed to sitting on the hall table until after polling day) only if a party member puts the sticky tape on it, walks into the mildly willing voter’s front room and sticks it up. Fewer activists mean fewer posters.

Yet the most important lesson is about campaign strategy. Geake’s small posters may have been a revolution in 1910 but many candidates feel that they are outdated. For the Lib Dems they remain useful. They are trying to overcome the old idea that a Liberal vote is a wasted vote, so a dense forest of Day-Glo orange posters makes a valuable political point. Not so for Labour and, particularly, the Conservatives.

If a Tory candidate in a marginal is trying to target his voters with letters, visits and tailored literature the last thing he wants is to wake up Labour voters, suggesting that there is a tough fight going on. If the others start, he will retaliate, but only then.

Times Recommends

• Postman Pat moved to a high-tech sorting office
• Saatchi’s old favourites
• New teaching style gives pupils wake-up call