Nick Griffin compared some of the country’s most senior military officers to Nazi war criminals yesterday after they warned that the British National Party was tarnishing the reputation of the Armed Forces.

The angry outburst, which coincided with a purported leak on the internet of the far-right party’s membership list, came after The Times revealed concerns by a group of former generals that far-right extremists were hijacking the military.

On the eve of his appearance on the BBC’s Question Time, Mr Griffin said in an online statement: “Those Tory generals who today attacked the British National Party should remember that at the Nuremberg trials the politicians and generals accused of waging illegal aggressive wars were all charged — and hanged — together.”

The letter, obtained by The Times on Tuesday, was signed by General Sir Mike Jackson and General Sir Richard Dannatt, the former heads of the Army, Lord Guthrie of Craigiebank, former Chief of the Defence Staff, and Major-General Patrick Cordingley, commander of the Desert Rats in the Gulf War.

They expressed concern that far-right extremists such as the BNP had sought to “hijack” the military’s good name by associating their political campaigning with the Forces.

Mr Griffin reacted furiously, saying that the comments were “nothing but a dying Tory toady gasp”. He added: “Along with the political leadership of Nazi Germany, the chiefs of staff of the German Army, Alfred Jodl and Wilhelm Keitel, were also charged with waging aggressive war.

“Sir Richard and Sir Mike fall squarely into this bracket, and they must not think that they will escape culpability for pursuing the illegal wars in Iraq and Afghanistan.”

General Cordingley said that he was disappointed that the debate had descended into “vitriol”.

He said: “It rather sums up the comments that the four of us were trying to make: the Armed Forces should not be used for any form of persuasion in the political debate.”

In a second attack on the BNP yesterday, a document purporting to be a recent membership list was leaked on the internet, listing the names and addresses of thousands of people. It purported to date back to April and contained more than 16,000 entries, although many were duplicates. Analysts claimed that once the duplications were removed, the membership number was about 11,000.

The BNP denounced the list, which included several doctors and military personnel, as a malicious forgery. Mr Griffin said it contained names from a leaked membership list from 2008, as well as the names of people who had rung up to inquire about the party. He claimed that many names had been completely fabricated.

However, numerous posters on Stormfront, a far-right blog, expressed concerns that their names had been published. The list showed the highest concentrations of membership in Leicestershire, Lancashire, Derbyshire and Lincolnshire, and also revealed that hundreds of people had let their membership lapse this year.

The Information Commissioner’s Office (ICO) announced that it would investigate the latest leak of private BNP data. The membership was previously leaked in November 2008 after a power struggle within the party.

Searchlight, an organisation which tracks the BNP, suggested that the latest leak was due to a new power struggle, between members in Northern Ireland and elsewhere.

The list named 39 members from Northern Ireland, including a serving soldier and a former police officer. The BNP has recently branched into the Province and its membership call centre is located there. It prompted accusations by some party members that the call centre was the source of the leak. A source in Belfast, however, accused mainland members of trying to undermine them.

The list appeared to show that the party had seen a surge in female recruits, with more than 2,000 women members. It also included some international addresses — many in the US, Canada and Australia.

Mick Gorrill, the assistant information commissioner, said: “The ICO is investigating this further breach of the BNP membership list. We will establish the full facts before deciding on any regulatory action.”

When the list was first leaked, it showed just over 12,000 members. More than 160 complaints were made to police about attacks on BNP members and their property after the leak. Last month Matthew Single, a former member of the BNP, admitted releasing the data and was fined £200 for breaching the Data Protection Act.

Last night a website that allowed users to search for BNP members near their postcode area was registering up to 20 searches a minute.

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