Among those undecided, 48 per cent live in northern Croatia and the regions of Lika, Kordun and Banovina, 41 per cent are aged between 15 and 24, 48 per cent have primary school education or less, and 42 per cent have low income.
Thirty-seven per cent of those with centrist leanings come from the Zagreb area, 36 per cent have a university degree, and between 33 and 37 per cent have high income.
Among those with leftist views, 27 per cent come from Istria and 26 per cent from the Zagreb area, 26 per cent have a university degree, 22 per cent are above the age of 45, 40 per cent are atheists.
Thirty-four per cent of respondents supporting rightist views come from Dalmatia, 23 per cent are aged from 35 to 44, and 24 per cent claim to be true believers.
The survey was conducted last month on a sample of 1,000 Croatian citizens above the age of 15.
Similar surveys were conducted in 2002 and 1995.
Five years ago, 29 per cent of respondents expressed their support for centrist ideas, while leftist and rightist views were equally supported by 17 per cent. The number of those undecided was slightly higher than today -- 37 per cent.
In 1995, 55 per cent had centrist leanings, while 22 per cent supported the centre-right and 17 per cent the centre-left.