The Prime Minister signalled a new focus on banking sector tax revenues, saying that unpopular decisions on bonuses would make it difficult to keep a regime "that they might favour".
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His comments backed Deputy Prime Minister Nick Clegg's warning that the Government would not stand on the sidelines if banks refused to restrain their pay levels.
Mr Cameron insisted the banks had to understand the "political context" to the issue of bonuses, given that the banks were bailed out by taxpayers who are now feeling the pinch.
The British public found it "very galling" to see bankers paying themselves "unjustified bonuses", he said.
"We have had to bail out the banks and use taxpayers' money in a difficult economic situation and I do believe in social responsibility, that people have to think of their responsibilities when they make these decisions.
"And of course every decision like that the banks make makes it more difficult to keep a tax regime that they might favour.