Foreign aid spending could outstrip the defence budget within 15 years, according to an analysis published last night. Research conducted by the House of Commons Library found aid spending could eclipse defence by 2030/31, assuming current spending changes continue under successive governments. According to the analysis, defence spending will be £27.1 billion by 2031, but the aid budget will be £28.3 billion, the Daily Telegraph reported. Prime Minister David Cameron, who has dismissed concerns about the impact of cuts on the capacity of the British forces . In recent years, the Department for International Development has seen its budget increase sharply as ministers try to hit the target of spending 0.7 per cent of GDP on aid. Last week the Mail revealed that the Tory manifesto will not commit to keeping defence spending at the Nato target of 2 per cent of national income. Yesterday David Cameron dismissed concerns raised by the head of the US Army about the impact of cuts on the capacity of British forces, insisting it remained a 'very strong and capable partner' for the Americans. In a sign of the pressure on the Prime Minister over the military budget, former Defence Secretary Liam Fox said he and fellow Tory MPs would find it 'hard to swallow' if Mr Cameron allowed spending to fall below the 2 per cent Nato threshold while maintaining a pledge to spend 0.7 per cent of GDP on aid. Former defence secretary Liam Fox, pictured, has said he and fellow Tory MPs would find it 'hard to swallow' if defence spending fell below the Nato threshold . Ministers are under increasing pressure from Tory MPs and senior military figures to commit Britain to meeting the Nato target after 2016. With deep cuts to Whitehall budgets to continue after May's general election, Chancellor George Osborne is reported to have warned privately that it may fall below that level. The most senior civil servant at the Ministry of Defence said that the department would 'clearly' like the Nato target to be met - although he said that it would be for ministers in the next government to decide. Giving evidence to the Commons Public Accounts Committee, Jon Thompson, the permanent secretary at the MoD, said: 'Clearly, we would like 2% of GDP but that's for the next government to decide.' He said that on current forecasts, GDP growth was expected to outstrip the growth in the defence budget, so that it would drop below 2% at some point in the next parliament. He warned that further cuts in spending could ultimately affect the capability levels of the armed forces. 'It rather depends on how deep the cut is and how much further financial efficiency we can drive. If it were to be more than the level of financial efficiency we can drive, then yes, it will impact on capability,' he said. Speaking at a campaign event in Colchester, the Prime Minister said the UK's defence budget was the fifth largest in the world and second only to the US in the Nato alliance. He said: 'In terms of spending, the promise we have made is that the equipment budget, which is £160 billion over the next decade, that will grow by 1% in real terms in each year of the next parliament. 'Also we have said we don't want to see further reductions in our regular armed forces. So we have that commitment: second largest in Nato, fifth largest in the world. 'And as for working with the Americans, I know because I spend time with President Obama and others, how much they appreciate the fact that Britain is a very strong and capable partner and able to fight with them, when it's in our national interest, anywhere in the world.'
According to analysis, defence spending by 2031 would be £27.1 billion . If spending changes continue, foreign aid budget would be £28.3billion . Department for International Development has seen sharp budget increase . Tory manifesto will not commit to keeping defence spending at 2% of GDP . Prime Minister has dismissed concerns about impact of cuts on British forces .