The Archbishop of Canterbury has warned it would be a 'tragedy' if Britain backed off its commitment to spend 0.7 per cent of its spending on overseas aid.

Justin Welby's remarks came as Oxfam's chief executive Mark Goldring admitted the scandal around sex abuse committed by the charity's staff in Haiti had undermined public support for the government's international development budget.

Speaking to MPs this morning on the international development select committee Goldring revealed around 7,000 people have stopped making regular donations to Oxfam and admitted 26 fresh allegations of recent and historic incidents have been made by Oxfam workers — 16 of them outside the UK — since the story broke in the Times newspaper earlier this month.

Oxfam is facing a Charity Commission investigation and the scandal has raised questions about the government's commitment to spend 0.7 per cent of GDP — around £13bn each year — on overseas aid.

But Welby robustly defended the pledge, written into law in 2015.

'The answer to doing a good thing badly is not to [not] do any good things. It is to do good things well,' he said after Goldring's grilling by MPs.

'To back off from that would be a tragedy. It would be retreat behind our walls and it would be an ignoring of the vast difference we can make and the vast and positive influence we can have as a nation which we deploy very effectively through the 0.7 per cent.'

Welby has been a staunch advocate of the 0.7 per cent commitment and said the revelations into abuse committed by aid workers did not weaken his view.

But he did condemn the abuse committed by Oxfam and other NGOs as 'appalling' and said he suspected it will emerge that 'there is not a lot that is new about this'.

He said: 'If you put people under huge stress in places of great difficulty some of them will behave very badly indeed and wickedly.

'We are scarcely as an institution in a place to throw stones at people who have been caught out on issues of abuse. Let's be honest. One of the lessons we have learnt is that transparency matters.'

The Church of England will go before the Independent Inquiry into Child Sexual Abuse next month to answer questions about how it dealt with allegations of abuse in the Diocese of Chichester.