US banks have paid the bulk of the £2.5bn (€1.9bn) the UK has collected from its bonus tax designed to curb excessive pay, hitting banks' second quarter earnings while creating a windfall for the UK's new government.

According to statements in the past few days from JP Morgan Chase, Citigroup, Bank of America and Goldman Sachs, the four banks collectively paid at least $2bn toward the tax in the second quarter. Morgan Stanley, due to report second quarter earnings today, is expected to say it, too, will have paid several hundred million dollars.