Gordon Brown and David Cameron have succeeded in changing their public images over the past year to move closer to the position of the average voter, where Tony Blair successfully placed himself for so long. A new Populus poll for The Times, undertaken over the weekend, shows that voters have reassessed their opinions of Mr Brown and Mr Cameron, making the centre ground more crowded, with the Liberal Democrats seen as further to the left.

As in the past four years, Populus has conducted a special poll of voters’ views about the main parties and their leaders before the annual conference season. Full details of the poll of 1,004 adults between September 7 and 9 will appear on the Monday of each conference and then on www.populus.co.uk.

To set the scene, voters have been asked to place themselves, the three main parties and their leaders on a left-right spectrum. Political opinions are more complicated than just this measure (for instance, covering liberal versus authoritarian), but the specturm provides a revealing pointer about how voters view politics and how their opinions change.

On a 0 to 10 scale, from left to right, the average voter has moved slightly farther to the right of centre, to 5.37, from 5.27 a year ago.

The most striking change has been the convergence of voters’ views of the two main parties and their leaders. They now put Mr Brown at 5.16, 0.31 points to the right of last year, and virtually the same place on the spectrum as the Labour Party (at 5.20). Mr Brown is the closest of the three leaders to the average voter, just 0.17 to the left. A year ago, Mr Blair was in almost exactly the same position as the average voter.

There is also good news for Mr Cameron as he has sought to change his party’s image and appeal to the centre ground. Voters now put him on 5.63, 0.37 to the left of a year ago. This means that he has halved the distance between voters’ image of him and where they put themselves.

The public puts the Conservative Party at 5.76, a leftward shift of 0.33, their closest to the centre in any of the five surveys so far. The gap between Mr Cameron and Mr Brown has thus narrowed from 1.15 to 0.47 over the past year and the gap between the Tories and Labour from 1.12 to 0.56.

Conservative voters have, however, moved 0.25 to the right to 6.30, and, as before, put their own party farther to the right. Tory voters also put Mr Cameron much farther to the right than the public generally, at 6.51, a gap of 0.88.

Voters believe that Sir Menzies Campbell and the Liberal Democrats have moved slightly leftwards, away from the average voter. The Lib Dems, at 4.53, are now 0.67 to the left of Labour, nearly double the gap of a year ago. Lib Dem voters are, at 4.63, farther to the left than previously and they see their own party as slightly to the right of centre. Lib Dem voters put Sir Menzies well to the right of themselves at 5.28, a wider gap than a year ago.

Older people put themselves much farther to the right than younger people: at 5.96 for the over 65s, against 5.03 for 18 to 24-year-olds.

Times Recommends

• Bank charges hit us for being human
• Sorry, Father, thou still shalt not steal
• The shed where Santa’s failures go to die