Buckingham Palace today barred the BNP leader, Nick Griffin, from a garden party hosted by the Queen.

The palace said it had withdrawn Griffin's invitation because he had "blatantly" sought to use his attendance for party political purposes.

Griffin described the decision as "an outrage" and "thoroughly anti-British" and blamed the government for putting pressure on Buckingham Palace to withdraw his invitation.

The palace denied him entry following an interview given by Griffin to GMTVtoday and after he posted a message on the BNP website asking supporters for questions to ask the monarch.

Buckingham Palace issued a statement that said Griffin's use of the invitation for "party political purposes" had increased the security risk as well as the possible "discomfort" of other guests.

Unite Against Fascism said the decision to bar the far right leader was "fantastic".

Griffin told GMTV that his attendance would not embarrass the Queen, citing his democratic mandate. He and fellow BNP member Andrew Brons were automatically eligible for a garden party ticket in their capacity as elected members of the European parliament.

In an entry on his blog on Wednesday, Griffin told BNP followers that he would attend "to represent the patriots who made this possible; I'll be there for you" and asked for their thoughts on what he should say "if – presumably due to some ghastly blunder by a courtier – I actually meet her?"

Today Buckingham Palace said it had decided to rescind the invitation. In a statement, the palace said: "Nick Griffin MEP will be denied entry to today's garden party at Buckingham Palace due to the fact he has overtly used his personal invitation for party political purposes through the media. This in turn has increased the security threat and the potential discomfort to the many other guests also attending.

The statement added: "Mr Griffin's personal invitation was issued to him as an elected member of the European parliament. The decision to deny him entry is not intended to show any disrespect to the democratic process by which the invitation was issued. However, we would apply the same rules to anyone who would try to blatantly politicise their attendance in this way."

Griffin was due to be among the 8,000 guests at the event, hosted by the Queen and also attended by the Duke of Edinburgh.

A Buckingham Palace spokeswoman said that Brons's invitation to the garden party had not been revoked as he had not "exploited" it for political ends.

But Griffin's guests – thought to be his wife and children – could not attend as he had been barred. Other members of the royal family who will be mingling on the palace's lawns include the Duke of York, The Duke and Duchess of Gloucester and the Duke of Kent.

Griffin said the Palace's reason was "invented nonsense" and that it was "thoroughly anti-British" to hold him by different standards to everyone else.

The MEP for the north-west said he did not "blame the Queen" and claimed Buckingham Palace was under "enormous pressure from the Lib-Con coalition" to withdraw his invite.

He maintained he had a mandate from a million British people and had a right to attend.

"Nowhere in the book of rules given to all attendees does it say anything about not giving media interviews and of course countless people have done precisely that in the past," he said.

He added: "It is an attack on the right of every person in Britain to get the news of current events reported by the media, and it is an attack on the one million plus patriots who voted for the BNP. The move has obviously been made under pressure from the ConDem regime who are desperate for any reason to bar the BNP."

To add to Griffin's woes, he was confronted by human rights campaigner Peter Tatchell, who accused him of being a "gutless coward" as he was leaving BBC studios at Westminster yesterday afternoon.

A Unite Against Fascism spokesman said it was delighted by Buckingham Palace's move.

"I think this is a fantastic decision that's been taken. The invitation in the first place was a blow for those who suffered in the Holocaust and more recently those who have suffered at the hands of racists and homophobes.

"The fact he was invited anyway is a little bit concerning. The palace needs to understand and the establishment in general, who are giving these privileges, that the whole point of him being so excited about going is because it gives him the chance to legitimise himself."

Griffin pulled out of a similar event last year following a public outcry, claiming he had "no wish to embarrass the Queen" by attending.

Speaking on GMTV this morning, Griffin said: "This time it's totally different – 800,000 people voted for us in the European elections and I was voted an MEP."

He added: "The palace have made it very, very clear that they will not discriminate against any elected MEP and I think that's the proper thing to do, so there's no embarrassment there at all."