The pair - David Keogh, a former employee of the cabinet office, and Leo O'Connor, a researcher for a former Labour member of parliament - have been charged under Britain’s Official Secrets Act.

The leaked memo details a conversation that Bush had with Tony Blair, the British prime minister, in April 2004.

In course of the conversation, Bush reportedly mooted the idea of bombing the headquarters of Aljazeera in Doha, Qatar. Blair subsequently talked the US president out of taking such military action against the Arab broadcaster.

Stung by the leak, the United States denied that Bush had ever seriously contemplated bombing Aljazeera. The British government also imposed a gag order on the media, prohibiting any further publication from the memo.

Leak

The London-based Guardian newspaper meanwhile reported that two Labour MPs had defied the Official Secrets Act to pass on key contents of the memo.

Tony Clarke – a former MP for Northampton South – first obtained the memo and consulted his parliamentary colleague, Peter Kilfoyle. The two MPs then decided in October to reveal key information in the memo to a Democrat supporter in the United States.

The controversial contents of the memo were finally published in London’s Daily Mirror soon after Keogh and O’Connor were charged.

The leak cast fresh doubts on US claims that past US attacks on Aljazeera offices were accidental.

In November 2001, Aljazeera's office in Kabul was bombed. In April 2003, Aljazeera journalist Tariq Ayub was killed in Baghdadh when its office was struck during a US bombing campaign.