Police Scotland will reach its target of more than £1 billion of savings two years ahead of schedule, a report has said.

The creation of a single police force across the country has so far saved £72.6 million, figures from this year's Scottish Police Authority (SPA) draft budget show.

Eight regional police and fire services were abolished last year and replaced by single national units in a cost-saving drive by the Scottish Government.

Officer numbers have remained stable but civilian jobs have been cut. There have also been changes to opening times at the country's 214 local police station counters, with the number of control rooms to be reduced to five.

The SPA report states: "The Police Reform process expected total net savings of £1.1 billion by 2026. The service has already delivered savings of £8.7m in 2012/13 and further savings of £63.9m in 2013/14.

"The cumulative full-year effect of these savings already exceeds the target cost reductions of £1.1 billion by 2026. We will exceed the expected level of reform savings by 2026."

The report outlines how the Police Scotland budget of £1.15 billion will be divided over the next financial year and it will be put to a vote at the authority's next board meeting in Inverness on Wednesday.

More than £68 million is planned to be saved in the coming year.

The report reads: "A single policing service has brought a number of opportunities. Duplication has been reduced and management streamlined.

"Instead of a number of different policy practices and approaches across Scotland, there is now a unified and corporate approach not only to policing policies but also to enhance people and organisation development.

"In summary a total cost reduction of £68.2m is required in 2014/15 against which £58.4m has been identified. The remaining target will be allocated to managers for further cost reductions and represents less than 1% of the total budget for 2014/15."

Earlier this week, a trade union urged its members working for Police Scotland to vote for industrial action following concerns over control room closures and changes to terms and conditions.

Unison Scotland has written to police staff today telling them that trust between Police Scotland and the trade union has broken down.

Unison highlighted three areas of concern, including the proposed closure of four control rooms which take emergency calls, changes to police staff redundancy terms, and the restrictions on the annual leave of 1,700 staff due to the Commonwealth Games this summer. Members will be balloted later this month.

Policing of the Commonwealth Games will be financed outside of the regular Police Scotland budget.

The report states: "The 2014/15 Revenue Budget has no impact on the Commonwealth Games. Additional expenditure incurred by the Authority in respect of the Games will be reimbursed by the Scottish Government."

George McIrvine, secretary of Unison police staff Scotland branch, said: ''Our members across Scotland are telling us loud and clear that enough is enough.

''Staff are stressed, over worked and under pressure. We will ballot them to gauge their strength of feeling on potential strike action. The employer have given us no choice."