UK aid charities have described the suggestion that David Cameron could use Britain's aid budget on military operations as 'deeply concerning' and 'morally wrong'.
The Prime Minister indicated he is ready to consider using money from the UK's official aid budget to fund military operations to stabilise war-torn states.
But charities including Oxfam and ActionAid today insisted 'not a single penny' of aid money should be diverted into the military.
Mr Cameron said it is right to look for ways in which the Department for International Development (DfID) can work more closely with the Foreign Office and Ministry of Defence.
He said initiatives which provide the basic level of security needed for development to take place can be an
"important" use of aid funds.
Key charities have rejected his proposals, however.
ActionAid said defence needs should have 'no bearing on how aid is spent'.
Spokesperson Melanie Ward said: "The purpose of UK aid is to reduce poverty and this is enshrined in law.
"To pilfer from aid to pay for defence would be morally wrong and practically misplaced.
"Of course, when UK forces are in action they should always coordinate closely with international development experts to make sure that the needs of local people are met, but a raid on aid would provide no solution.
"Instead it could well deprive some of the world’s poorest people of life-saving support and undermine UK efforts to promote human security globally."
Oxfam echoed these sentiments, with their head of policy Max Lawson adding: "We should not see a single penny diverted into the military.
"If the Government needs to raise more money it should clamp down on tax avoiders rather than make insane choices between the safety of a family and their health and education."
Christian Aid voiced 'deep concern' over the plans, adding: "Aid diverted to ‘security, peacekeeping and demobilisation’ could have long term implications.
"The blurring of the lines between military action and aid delivery could mean that aid workers become associated with those forces, meaning they are not only put at risk, but find it hard to gain the trust of the people they are trying to help."
Any cut in the DfID budget would threaten to breach Mr Cameron's pledge to meet the United Nations target of spending 0.7% of national income on overseas aid, which Britain will meet for the first time in 2013.
But NGOs fear that the PM may meet his pledge while reducing the funds available for aid activities, by reallocating some of the responsibilities of the MoD or Foreign Office to DfID.
Asked whether he felt there was room for money in the aid budget to be spent on defence activities, Mr Cameron said: "I think we have to demonstrate that the DfID budget is spent wisely."