Bob Geldof has branded the Government's response to the refugee crisis in the Mediterranean, Middle East and Europe as "inadequate".
The Live Aid founder's intervention came after David Cameron announced the UK would resettle up to 20,000 refugees over the next five years, a response criticised by the Archbishop of Canterbury as "very slim".
Speaking at the GQ Men of the Year Awards, where he was presenting Chancellor George Osborne with the politician of the year award, Geldof said: "It can't be a numbers game. I don't understand when you say 20,000 over five years, I don't know how that works out."
He stressed that he thought "it has to be a game of empathy and kindness" and ended saying "you could probably do a lot better on that issue".
Osborne took to the stage and described Geldof as "the guy who introduced my generation to the challenges of poverty in sub-Saharan Africa".
He went on to say: "I think, what's going on now on our TV screens as we see that tragedy unfolding and the way we are going to do more to direct many hundreds of millions pounds more to help those people and give them a home.
"I think that will help change people's attitudes in this country towards that aid budget and for me it's a really significant step forward, it's why people like me and my colleagues are in government trying to do these things."
Earlier, Mr Osborne told a committee of MPs local councils could be offered additional help from the Government to cope with the cost of resettling 20,000 Syrian refugees after the first year, when the costs would no longer be met by the international aid budget.
He said that this cut-off was required to comply with OECD rules on what counts as aid spending by countries seeking to meet the United Nations' target of 0.7pc of national income.
The Prime Minister said the new scheme, taking refugees from camps near Syria, would meet the country's "moral responsibility" and added the UK would not take part in a planned European Commission request for EU member states to resettle a share of the 160,000 migrants who have already arrived in the continent.