Sir Tony Blair's sister-in-law has sparked outrage after footage emerged of her describing October 7 as a 'legendary day' for Muslims.

Lauren Booth, a British-born journalist who has converted to Islam, said 'only Allah knows' how many 'millions' would pick up the Quran in the wake of the attacks, arguing that the world had reached a historic 'tipping point'.

The comments, made during an interview with Turkish media last year, have sparked outrage given that October 7 marked the deadliest massacre of Jewish people since the Holocaust.

They will likely also cause major embarrassment for Sir Tony following his efforts to play a key role in a Gaza peace deal.

Booth, 58, who is Cherie Blair's half-sister, told Turkish newspaper Yeni Safak that 'after October 7, this October 7, a legendary day in the Ummah's history, yes, we can say that people are now picking up the Quran because of the steadfastness and sabr [patience] of the people of Gaza'. 

The Ummah means the Muslim community in Arabic.

During the same interview, Booth, who now lives in Istanbul, also said she had been 'annoyed' with Palestinians over what she described as a lack of determination to 'hate all Jews or just take Jewish life'.

'I got a little bit annoyed with the Palestinians when I met them at first because I thought they had Stockholm syndrome,' she said, recounting an earlier visit to Gaza.

Lauren Booth, 58, Sir Tony Blair's sister-in-law, has sparked outcry after describing October 7 as 'a legendary day' in an interview with Turkish media

Booth, 58, made the remarks during an interview with Turkish newspaper Yeni Safak last year

Booth had been a regular on the London social circuit before her conversion to Islam in 2010. Pictured above with her former husband Craig Darby, at their home in France in 2009

 'Because not only were they not determined to hate all Jews or just take Jewish life, they said Allah will sort this out for us… we must be steadfast. And I was so angry that I said you really need to be resisting this in a different way.'

The footage emerged as part of an investigation led by Israeli journalist Elchanan Groner of the news site 'Hakol Hayehudi' (The Jewish Voice), in association with the Shomron cinema fund for a Channel 14 documentary directed by Avraham Shapira titled 'Ashraf Marwan' – A Cover Name. 

When asked by the Daily Mail to explain her comments, Booth said: 'I continue to advocate for the right of Palestinians to live free from occupation. The UN recognises the right to resist against foreign forcible actions that deprive people of their right to self-determination.

'Within that understanding, I do not advocate for violence against any religious or racial group.'