Andrew Mitchell has denied acting as a "rogue minister" as he defended unfreezing £16m in aid for Rwanda on his last day as International Development Secretary.
The senior Tory, who recently quit as Chief Whip after a row with a police officer, insisted the decision was made collectively by the Government.
Appearing before the International Development Select Committee, he argued that it was made with "absolutely propriety" and criticised "heated" media coverage.
Number 10 and the Foreign Office were "kept in the loop", he told MPs, and denied Britain had "gone out on a limb" by continuing its support of Rwandan President Paul Kagame.
The aid sparked controversy because it was given despite allegations that senior government figures in Rwanda were supporting a rebel militia in the neighbouring Democratic Republic of Congo (DRC).
A leaked interim United Nations report had claimed Rwandan defence minister General James Kabarebe was a de facto commander of M23 - a Congolese rebel group accused of rape, murder and other atrocities.
Other countries reviewed their own aid arrangements with the African nation but in late August, on his last day in his current job, Mr Mitchell reinstated the grant from Britain.
He revealed that, highly unusually, he had learnt a week before the September reshuffle that he was going to be made Chief Whip and had therefore addressed outstanding issues.
Asked why the Government acted before the final UN report was issued, the MP said Rwanda was "one of the best places in the world" to ensure British money was spent on aid.
"Taking away budget support does not harm the elite, the decision makers, and would damage the poverty programme," he argued, claiming oversight of the way in which aid was spent in Rwanda meant it could not go to supporting militia groups operating in the DRC.
He added: "We took a decision which we thought was right, bearing in mind our aim of helping alleviate poverty in a country with which Britain has become a close but candid friend since the 1994 genocide. I think the decision we made was the right decision."
In the session lasting a little over an hour, Mr Mitchell looked relaxed as he explained he had acted with the knowledge and approval of the Foreign Office and the Prime Minister.
The £16m amounted to half of Britain's annual support to Mr Kagame's administration.
Mr Mitchell said it had already been delayed from July because of concerns in the DRC.
Because of a failure to comply fully with conditions set out by Britain, it was decided to channel half the money straight to education and agriculture projects, he added.
"The British Government decided - not some rogue minister - what was the right response," he said.
"We made that response very much on the understanding that there will be the second tranche to be discussed in November and December in the light of the group of experts' report. That was why we took the decision we did.
"The decisions were made entirely properly through cross-government consultation, all relevant departments and ministers being consulted and that was how we reached our decision."
The MP also challenged the suggestion that other international donors had frozen their aid to the country pending the UN report.
He said the United Kingdom did not "go out on a limb" and was "in the middle of the pack" in terms of policy on Rwanda.
He told the committee that he did not have any conversations with Mr Kagame and his ministers without the knowledge of officials at DFID.
"Everything I had done in making the decision, I did in consultation with my colleagues, with total propriety," he said.
The committee might ultimately agree Mr Mitchell acted properly over the grant but it could still criticise the decision itself once the final report on Rwanda is handed to the UN.
New International Development Secretary Justine Greening will decide on the second slice of aid for Rwanda, due at the end of 2012, once the report is issued later this month.