My answer was unclear and for that I apologise

Lord Macdonald

In fact, there had been 38 special advisers under the last Conservative Government, leading to Tory claims that the mistake displayed the government's culture of "downright deception".

Lord Macdonald's remarks were changed in Hansard, the official record of parliamentary proceedings, but the minister insisted no pressure had been put on the editor to make the amendment.

The incidents comes after the debate over special advisers was rekindled by Jo Moore, the Transport Department special adviser who suggested in an e-mail that the day of the US terror attacks was a good time to "bury" bad news stories.

'Dispelling confusion'

In a personal statement in the House of Lords on Monday, Lord Macdonald said he wanted to "dispel any confusion" he had produced.

"My answer to Lord Boardman was unclear and for that I apologise," he said.

Jo Moore rekindled the debate on special advisers

"Lord Boardman asked for the cost of special advisers over the last 12 months, compared to the cost under the previous Conservative administration.

"The term 'administration' has a specific meaning for special advisers as under the terms of their model contract appointments are terminated at the end of an administration.

"Therefore in this context administration is synonymous with Parliament.

"I gave a cost of �4.4m for the current figure of 81 special advisers as compared with 79 under the last administration.

"My intention in offering these numbers was to counter any suggestion of a large increase in the total number of special advisers between this current administration and the last administration, both Labour of course."

Cost rise

Lord Macdonald said the special advisers' cost for the last year of the Tory government was �1.8m, compared to �4.4m now.

He added: "The Hansard editor and the civil servant who routinely checks the speeches of Cabinet Office ministers sought to clarify matters by changing "previous administration" to "previous Parliament" in the final record.

"And for the avoidance of doubt let me say there was certainly no pressure brought to bear on Hansard to make such a change.

The minister later said in a written parliamentary reply that 14 senior special advisers - those earning more than �60,000 - had left the government since Labour won power in 1997.

'Culture of spin'

Shadow cabinet office minister Tim Collins welcomed the apology but said he wanted to make sure such an incident did not happen again.

Earlier, Mr Collins told BBC Radio 4's World At One programme that Lord Macdonald was one of the most intelligent people in the government and so unlikely to have made a "simple slip of the tongue".

"It is also rather serious that his officials seem to have gone round and instructed Hansard to rewrite the record to pretend that he had said something different from what he did.

"This all goes to the heart of this culture of spin and downright deception which has been at the heart of this administration."