Hugh

The reasons were, from the article "Mr Cameron said the Conservatives had sought advice from Commons officials on whether to also declare the money to the members' register - and been effectively told they did not have to.
Mr Osborne is now seeking a ruling from the Commons standards committee on the matter."

And from the Sunday Mail story
"He said that Commons registrar Alda Barry told him last month that he did not need to name the seven donors. Mr Osborne said there were emails to back up his position.

But yesterday, after this newspaper obtained the donors' names, the Shadow Chancellor said that Ms Barry had now admitted she could have been wrong. 'I was told that my declarations were in order,' he said in a statement. 'Ms Barry has now told us that her initial advice may have been unclear.
'These donations are to the Conservative Party, they are openly declared and we have followed the rules as they were explained to us.
'All the donations over £5,000 have been declared to the Electoral Commission and are available for all to see on their website, as the law requires.' Ms Barry declined to comment last night. "