An independent Scotland will give £7 million for every billion it earns to foreign countries in aid, according to an SNP minister.

MPs from Westminster's select committee on international development are visiting Edinburgh today to quiz Humza Yousaf, Scotland's minister for external affairs and international development, on the SNP's plans for an independent Scotland.

Speaking ahead of the committee, Mr Yousaf attacked successive UK governments for failing to meet the UN's target of spending 0.7% of gross national income on aid for 42 years.

The SNP would enshrine the target in law if it gained power in an independent Scotland, according to Mr Yousaf.

He said: "With independence we will legislate to enshrine the UN's 0.7% aid target in law, effectively future-proofing the aid budget. That contrasts to the UK's record on aid, which is one of missed targets.

"For 42 years the UK failed to meet the UN aid target to spend 0.7% of gross national income on aid - a failure which led to 'missing aid' of £87.5bn since 1970, according to House of Commons library research.

"This year the UK should finally reach the target, something our Scandinavian neighbours did decades ago.

"However they have also failed to enshrine the target in legislation, despite promising to do so in the Coalition agreement and in both the Tory and Lib Dem manifestos.

"We know that the Conservative right wing have consistently attacked the aid budget despite its life-saving work, and therefore without future-proofing the aid budget there is huge uncertainty over its future.

"We know aid saves lives, be it in humanitarian emergencies, in long-term efforts to get children into school or to improve healthcare."

Meanwhile, Scotland's prison officers have voted to back the independence campaign by nine branches to six in a vote at the conference of The Scottish Prison Officers' Association.