LONDON (Reuters) - Britain's public sector net cash requirement rose unexpectedly last month compared to the same time a year ago, hitting its highest June level since records began in April 1984, official data showed yesterday.

The Office for National Statistics said the public sector posted a net cash requirement of £20.905 billion in June, up from £20.213 billion last year and well above economists' forecasts for a fall to £15 billion.

The figures are likely to disappoint analysts who hoped that the improvement in Britain's fiscal position would continue in June. However, for the year to date both PSNB and PSNCR are lower than they were at the same point in the last fiscal year, when Britain was still deep in recession.

Sterling fell to a session low against the euro after the data and also weakened versus the dollar.