Downing Street's version of events in the dispute over the prime minister's role at the Queen Mother's lying-in-state was about to be challenged by a figure at the centre of the row, it has emerged.

The claim was made just hours after Number 10 dropped its complaint over press reports that officials tried to seek a more prominent role for Tony Blair.

The prime minister's official spokesman had earlier said they were "very happy" that it had been accepted that there had been no attempt to enhance the prime minister's role.

But it has been disclosed that Black Rod Sir Michael Willcocks - the parliamentary official in charge of organising the event - had made clear to the Press Complaints Commission that he was ready to give evidence.

Possible explanation?

According to sources, the information from Sir Michael, the former commander of Nato forces in Bosnia, was "unfavourable" to Number 10.

BBC News 24's chief political correspondent Nick Robinson said this might explain why Downing Street decided to drop its complaint to the PCC.

Number 10 had demanded an apology and correction of stories alleging that it argued for a more prominent role for Mr Blair in the Queen Mother's funeral arrangements at Westminster Hall.

Earlier, Peter Oborne, the journalist concerned in the original report, told the BBC that Downing Street's decision to drop the complaint showed that it was "accepting our story as 100% true".