FIRST Minister Donald Dewar's determination to introduce a proportional voting system for council elections carries clear support among voters, according to a poll by System Three exclusively for The Herald.

A total of 54% of committed voters say they support proportional representation for local council elections, while only 21% are opposed.

But one voter in four is undecided or does not yet know, leaving substantial scope for a national debate on the issue which is set to be one of the major themes of the Scottish Parliament when it reconvenes in September.

System Three has also found that support for the Scottish Liberal Democrats has slumped in the month since the protracted row over their coalition deal with Labour in the Scottish Parliament.

Support for Mr Dewar's main weapon in his drive to reform local government is strongest among the highest social group (66%) and lowest among the manual class.

When support is broken down by political party, the Scottish Liberal Democrats emerge as keenest on PR with 63%, while Tories - whose party policy is to resist PR - are next with 58% with the SNP and Labour on 57% and 56% respectively.

Men and women are fairly evenly in support (55% and 53% respectively), but age groups appear split, with the youngest voters aged 18-24 and those aged 65 and over showing no majority for PR. Both these groups registered only 48% support.

When support is measured regionally those most in favour of change are voters in the North-east and Lothians (65% and 69%) respectively. No majority for PR could be found in the West of Scotland, South of Scotland, or Highlands and Islands.

In Glasgow, where Labour won 94% of the seats on the city council with only half of the vote, there is a majority (53%) for PR.

But the West of Scotland also produced the highest number of Don't Knows and Undecideds (35%).

A Labour spokesman said the System Three poll suggested there was a mood for change in local government voting in line with the views expressed by the McIntosh Committee headed by Neil McIntosh, whose report on the future of local government was published last week.

''A great deal depends on the work which must be carried out in the coming months by the committee established to build on the McIntosh foundations,'' he said.

''A lot of councils do a lot of good work, but clearly there is a need to back up these efforts by offering positive support to the many councils committed to improving public participation.''

The Conservatives remain unimpressed.

Scottish Tory leader David McLetchie said: ''The real problem with PR is that it disrupts the link between the councillor and the constituent. Under PR there is a range of systems and the poll shows clearly there is a lot of confusion among the electorate about what they all involve.

''This poll suggests that there are still more questions than answers on the PR issue. No-one has yet come up with a solution to the problem posed by the broken link between constituents and councillors.''

Poll details Page 7