A civil servant and a former MP's researcher have appeared at the Old Bailey to face Official Secrets Act charges over an alleged leaked memo.
The memo is said to have detailed comments by the US president
Cabinet Office communications officer David Keogh, 49, and Leo O'Connor, 42, both of Northampton, were remanded on bail at the pre-trial hearing.
The case is believed to relate to the disclosure of details of a conversation between Tony Blair and George Bush.
The US President reportedly discussed bombing Al-Jazeera's studios in Qatar.
But the White house has previously dismissed claims Mr Bush considered such a move against the Arabic TV station as "outlandish".
Mr Keogh is accused of passing a document to Mr O'Connor, 42, who used to work for the one-time Labour Northampton South MP Anthony Clarke, in 2004.
Mr Keogh is charged under Section 3 of the Officials Secrets Act with making a "damaging disclosure" of a document related to international relations.
Mr O'Connor is charged under Section 5 of the act with receiving a document without lawful authority.
The men will next appear in court on 25 April.