SCOTLAND'S largest local authority is facing a £152m budget black hole over the next three years.

According to the local authority's financial forecast, it is already planning for a gap of £51m next year, with gaps of £44m and £47m identified for the following two years.

The council's finance chief has told councillors that opportunities to make savings and cuts are "becoming increasingly difficult" in the latest forecast, which predicts the Scottish Government's pay award will also decrease by £25m a year, over the next three years.

Trade unions have now written to all councillors demanding any predicted gaps in their budget should not impact on workers' pay and grading schemes, which are intended to address the equal pay issues which have affected the council for decades.

Brian Smith, of trade union Unison, said the budget holes were "on top of around £400m in cuts to jobs and services in the last decade", and added: "This cannot go on."

It comes after the Scottish Government's official forecaster said in May this year that the government would be facing a £1bn budget gap over the next three years, which could result in tax hikes and spending cuts to local services.

The independent Scottish Fiscal Commission (SFC) said “less money will be available for future Scottish budgets” under a predicted shortfall in income tax receipts, described as a "devastating blow” by critics.

In a letter sent on Friday on behalf of all trade unions, Unison branch secretary Smith wrote: "The people of Glasgow, the services which they rely on and the workers who provide them are not to blame for the austerity politics of successive national governments or the decisions of previous Glasgow administrations to continuously defend gender pay inequality.

"A new pay and grading scheme to eliminate the scandal of gender pay inequality in our city will also be implemented over this period. The trade unions are clear that this will require significant additional year-on-year revenue funding. The trade unions will fight using any means necessary to ensure this is delivered.

"The trade unions have continually opposed the passing on of Tory cuts and believe that the anti-austerity mandate which Glasgow's, and indeed Scotland’s, politicians have should be used to ensure no more cuts in council jobs and services.

"Much more could be done in the short term to hold off further cuts via borrowing powers, through the refinancing of PFI/PPP deals, by the use of reserves and by the Scottish Government using its tax-raising powers more progressively.

"This would not be a panacea but a tactic to protect services while fighting for more money and revenue raising powers."

The letter added that the Scottish Government's funding grants, which have been criticised by both Labour and the SNP in the past for being unfairly disadvantageous towards Glasgow, were going to further impact the city.

It read: "The multi-faceted impacts on council services of higher levels of poverty and the city status of Glasgow are not sufficiently recognised at present."

Glasgow City Council dismissed the criticism and said the forecast was a normal part of their financial planning arrangements.

A spokesman said: “Any local authority forecasts its budget ‘gap’ – which, in its simplest form, is the difference between income and planned expenditure.

“Primarily, they are made up of inflationary and other fixed costs, such as pay awards. It is a normal part of the annual budget process to identify and then close those gaps.”