The council tax is set for the lowest rise its payers in Wales have known

Research by BBC Wales shows the average increase in Wales in 2004/5 is likely to be below 5%, with the lowest increase being set at 2.4% by Caerphilly County Borough Council.

Of the 19 councils which have so far made their budgets available to the public, only four intend to raise the tax above 5%.

Professor Steve Martin, an expert on local government finance at Cardiff University, said he suspected that it may have something to do with the local government elections due in May.

I'm not going to say that low tax bills are not more attractive at election times than high tax bills, of course they are Russell Goodway

He said: "It may be that the assembly has been able to be a bit more generous with Welsh local authorities than has its Whitehall equivalent with English local government."

In 2001, when Labour fought and won the last general election, the increase was 6% - a record low.

Last year, the average increase in council tax bills in Wales was 9.8%, and in 2002/3 it was 7.4%.

But this year, it is estimated that the average increase is likely to be as low as 4.6%.

Cardiff council's Labour leader Russell Goodway, finance spokesman for the Welsh Local Government Association, did not deny that the low rates of increase might help his party in its more fiercely fought contests with Plaid Cymru, particularly in the south Wales Valleys.

Rising council tax bills have seen protests around the country

But he said this year's settlement had to be seen against the background of the government's determination to reform the council tax system.

He said: "I'm not going to say that low tax bills are not more attractive at election times than high tax bills, of course they are, but I think you need to understand the pressure that local government has come under from government to address the issue of council tax.

"The driving force that has achieved this level across Wales is the fact that we are responding to a government initiative to look at different ways of allowing councils to fund local services, and we're promised that that solution will come forward in the next 12 months."

Powys has set the highest increase at 9.5%. Cardiff council has managed to limit next year's increase to 2.58%, when last year its rise was 12%.

BBC Wales' research can reveal that Cardiff, for example, has in effect used �1.9m that the Welsh Assembly Government wanted spent on bed-blocking to reduce council tax bills in the capital by around 2.37%.

Moreover, it is understood that a number of councils have dipped into their financial reserves to keep bills down.

Cardiff has invested just over �2m in the process, while Caerphilly has come up with �2.1m.