Gordon Brown has been criticised by a watchdog for misusing immigration statistics.
In a letter to the Prime Minister, Sir Michael Scholar, chair of the UK Statistics Authority, said Mr Brown had made inaccurate comparisons between immigration figures in a podcast last week.
The comments cast a shadow over Mr Brown's attempt to position Labour as the party of fairness and responsibility on immigration in an earlier speech in East London.
Sir Michael pointed to two errors in the Downing Street internet broadcast and said he hoped all parties would be "careful in their use of statistics" during the election.
Mr Brown had claimed net inward migration - the number of arrivals minus those leaving - fell from 237,000 in 2007 to 163,000 in 2008 and 147,000 last year, but Sir Michael said the correct figure for 2007 was 233,000. More seriously, he said the 147,000 figure used by Mr Brown was wrong because it is taken from a different data set which has not yet been adjusted.
And despite the Labour leader correcting his error in his speech, Conservative shadow home secretary Chris Grayling was not in the mood for forgiveness. "Britain should expect better from its Prime Minister. No wonder we need change." he said.
