Boris Johnson has applauded Norwood's charitable work, describing it as an example of the difference between western values and those of the Islamic extremists who perpetrated the Paris terror attacks.

A record-breaking 1,350 guests attended the children and families charity's annual dinner at Grosvenor House in central London on Monday, raising £3.4 million.

Taking the platform following a minute's silence for victims of the Paris attacks, Mr Johnson - who visited Israel last week - told them that he wanted to "speak from the heart". Praising Norwood, he observed that "if you want to see the contrast between the warmth and the humanity of our democracy and their [the terrorists'] nihilism, it is here tonight.

"Because in Raqqa, they treat the disabled with brutality and contempt, and here tonight we are gathered to raise funds for the disabled, to build schools for them, to pay for their helpers, their teachers, and to ensure that everyone, whatever their ability, can live the life they choose. And that, fundamentally, is the difference between them and us." Mr Johnson also took part in a Q&A with audience members.

Norwood's appeal video highlighted its £12 million shortfall after statutory funding, demonstrating the difficulties faced by welfare charities in a tough economic climate. Among those featured in the video was Lizi Jackson, a single mother of two supported by the charity. Because of Norwood, she said, "my family and I have the best possible chance of succeeding". A few years back, she was newly married, purchasing a house and pursuing a career. At that point she "never could have imagined" needing Norwood. "But no one can prepare for the realities that life can throw at you. Too often I lie awake worrying about what will happen to my children when I'm not here any more. Knowing Norwood will be with them through their whole lives allays so many of my fears."

Retailer Sir Philip Green, Labour MP Sadiq Khan and Chief Rabbi Ephraim Mirvis were also among the dinner guests. And the dessert course was spiced up by a four-song set by Bryan Ferry.

It was announced that Norwood has recruited a stellar couple to share its presidential duties - former Labour Party adviser Lord Mendelsohn and his wife, Nicola, Facebook's European vice-president.

Speaking ahead of the dinner, Lady Mendelsohn said the couple were "incredibly humbled" to have been approached.

"I've always been a huge admirer of the work the charity does in supporting vulnerable people and children with learning disabilities. The chance to do something with Jon and give something back to the community was too good to resist. Both of us grew up in very community-minded families and that's always been at the heart of everything we've done.

"Two heads are better than one. I work in the world of tech, so innovation is my best friend. We both bring very different skills and will approach challenges in different ways. I'm a strong believer that if you want something done, you ask a busy person."

She said her Facebook colleagues were "very warm and supportive" about her new role, adding: "I think Norwood already does a huge amount in the social media area, but I'm hoping that the skills I've picked up in 21 years of working will help the organisation."

Lord Mendelsohn - shadow spokesperson for business, innovation and skills - said he had been attracted by the idea of being involved in a charity that was "well run, with high standards and a great team who are very professional".

Norwood chief executive, Elaine Kerr, said the charity was "hugely excited to have Nicola and Jon as our presidents, knowing they share our vision to be there for those who need us.

"Individually they bring a wealth of work experience, knowledge and skills which will inevitably make very valuable contributions to the future of our organisation."

The Mendelsohns succeed media boss Richard Desmond, who stood down as president in March.