SCOTLAND is to be given a £100 million boost to the Army today as a war of words broke out over the UK Government's review of Britain's military bases.

Defence Secretary Philip Hammond will announce the Army's contingent north of the Border is to rise by almost 650 to about 3860.

The 20% increase is much lower than the prospect of a doubling to roughly 7000 troops in a multi-role brigade for Scotland, originally envisaged in the UK Government's 2011 Strategic Defence and Security Review.

Already under fire from the SNP for "short-changing" Scotland, the Ministry of Defence sought to grab the political initiative, denigrating the Nationalists' "back-of-the-envelope defence plan for an independent Scotland, which is long on promises and short of the resources to deliver them".

A senior defence source said: "If the SNP had their way, thousands of defence jobs and millions of pounds of investment in Scotland would be at risk. Instead of certainty and security all the SNP offers is a wing and a prayer. They would not make us safer but leave us less well-defended and less secure."

He pointed out that, against a backdrop of an overall reduction in the size of the British Army from 100,000 regulars to 80,000, Scotland was getting an increase.

"Although the location of the armed forces is decided purely on military requirements, even by the SNP's argument of a 'fair share', the number of armed forces in Scotland will be roughly proportionate," he added.

Deputy First Minister Nicola Sturgeon had accused the Coalition Government of "backtracking spectacularly" over its original proposal to double the Army's presence north of the Border.

The plan to create a super-base at Kirknewton near Edinburgh was dropped early last year. MoD sources said the return of several thousand British troops from Germany in the next three years would be concentrated in seven areas across the UK, one of which will be Edinburgh/Leuchars.

Mr Hammond's plan includes a "seamless transfer" of RAF Leuchars to an Army base in 2015 – this will involve a £60m upgrade.

He will also announce the retention of operational airfields at Leuchars and Kinloss, which is also being turned into an Army barracks. Part of Redford as well as Dreghorn barracks in Edinburgh will be retained.

Kinloss, which has already seen the stationing of 700 troops, will receive another squadron of engineers, around 150 personnel. Leuchars will receive two units from Germany, including the Scots Dragoon Guards, totalling about 500 personnel by the end of 2016.

Angus Robertson, the SNP's defence spokesman, said communities would be appalled by the move and "Scotland is once again going to be let down by the MoD".