COUNCIL leaders have agreed not to publish long-range projections on council tax rises.

The indicative rises had been expected to be more than 10-per cent.

However, the Convention of Scottish Local Authorities (Cosla) has agreed to break with practice and not issue the forecasts, when it announces an average tax rise of 4.5-per cent for 2005-06 on Thursday.

The move will affect all figures for 2007-08, a period which councils say has been so grossly underfunded by the Scottish Executive that it is financially unworkable.

Some councils may also choose to hold back figures for 2006-07 if funding is also tight that year.

One council leader said the unprecedented step had been caused by a "very difficult" settlement from the executive over the next three years.

"If we had put out the very scary figures for the third year we would probably have got into arguments [with ministers] about the veracity of the figures. There's no point in doing it and causing significant concern."

Cosla will today publish a series of newspaper adverts saying its share of the public purse will have shrunk from 39.7-per cent in 1997-08 to 31.9-per cent by 2007-08, and claiming that it cannot cut council tax and preserve existing services.

Andy White, leader of West Dunbartonshire Council and the Labour group on Cosla, yesterday urged the executive to give Treasury money earmarked for reducing council tax to disadvantaged councils such as his.

Mr White said the pounds-12.5m announced by Gordon Brown, the chancellor, last year - which the executive has yet to allocate - ought to go to the 10 councils with the worst poverty and deprivation.

An executive spokesman said funding levels were "tight but workable", and the indicative figures had been postponed until it was clear how much councils would be able to save in line with ministerial efficiency targets.

Meanwhile, councillors in Glasgow will announce what could be the country's lowest rise - 2.4-per cent - on Thursday.

The increase would bring the city's Band D level to just over pounds-1213 a year.

The average Band D figure for Scotland overall is expected to increase from pounds-1053 to pounds-1095.