Britain's government borrowed more than expected in August, pushing the deficit for the financial year to date further above official forecasts and adding to a tough backdrop for finance minister John Healey's first budget next month. Public sector net borrowing stood at £18.3 billion ($24.5 billion) in August, the Office for National Statistics (ONS) said on Tuesday, above all forecasts in a Reuters poll of economists which had pointed to a £15.5 billion deficit. With investors worried about the possibility of further borrowing by the new government, gilt futures sank 20 ticks after the data before recovering, and yields in the cash market rose modestly as it opened.