To our future new Mayor of London,

I love this city. Your predecessor called it "the greatest city on earth". The history and majesty of Westminster, the lights and craziness of the West End, the grandeur and influence of the financial heartlands, and the beauty of the parks and gardens, foster a sense of awe and passion for the place like no other.

My true love for London is less concerned with these things, however, as impressive as they are. Instead, it's rooted in the wonderful and inspirational people who grow up and live here, particularly the children, young people and families who courageously each day overcome the overwhelming challenges of living on our inner-city estates. I lost my heart to such people nearly 20 years ago when I founded XLP, a charity that works with them to help children and young people stay in school and succeed, stay away from gangs and criminality, and set goals and work hard to achieve them.

I'm so proud of Cherry, who overcame a childhood blighted by mental ill-health, alcoholism and domestic abuse to become apprentice of the year at Barclays and outstanding woman of the year at the Stephen Lawrence Trust awards. And Shayleigh, who has emerged from being bullied to find self-esteem and confidence, and an apprenticeship with Snow Camp. And Tex, for dealing with the anger after being stabbed and the violent death of his cousin, and choosing a different path. And Septhon, who having been abused, involved with gangs and in prison seven times, is mentoring other young men towards more positive futures. These young people, and so many others, have stolen my heart and are the reason I love this city.

The thing is though, these children, young people and families are easily overlooked; most Londoners and tourists never meet them – some call them 'the invisible people.' When you arrive in City Hall for your first day, a thousand people will be clamouring for your time. Amid this, if you are able to remember that those most in need of your attention are those that will never seek it – the unemployed, the lonely, the grieving and the invisible – then you will do this city proud.

Please don't forget them.

The country's unemployment rate is now 5.1 per cent, yet youth unemployment in London is at 18 per cent. Nearly 1 in 5 young people here are unable to start their working lives. Even with the growth of apprenticeships, without support through the application and interview process, and the early months of employment, their broken homes and chaotic lives will sabotage their efforts. What will you do for the vulnerable who need such help to enter and remain in work?

Please don't forget the unemployed.

There are 13,467 Londoners for every square mile, 621 musical performances happen every week and we attract more than 17 million visits from abroad every year. Yet 52 per cent of people who live here say they experience loneliness. Embracing and respecting all our different backgrounds, cultures and perspectives, we have to create communities where people bring out the best in each other, rather than push policy that drives ever increasing independence and isolation from each other.

For young people, irrespective of the challenges they face, a strong and positive sense of belonging to a community is the key to helping them to build positive futures. A good community provides positive role-models, a broader perspective on life, and a level of resilience and compassion for others that we all need to thrive. How will you ensure that future generations grow up able to overcome inner-city challenges as part of a strong local community?

Please don't forget the lonely.

Although youth violence statistics have decreased, this year alone we have experienced the pain of three of XLP's kids being tragically stabbed and killed.

I have sat with more mothers than I can bear over the years, grieving the violent loss of their children, and walked the long walk with them as they try and make sense of what has happened. You see, there are some amazing and remarkable children, young people and families living in our inner cities with incredible potential, but that potential is often overwhelmed by a pervasive sense of fear, a lack of hope for anything different, and an 'I've got nothing to lose' mentality. That is a culture where gangs, criminality and violence can spread like a disease.

Those who have turned their lives away from knife crime say the same thing – "there was this one person who was there for me" and "I found something to lose." Our young people need to know they are valued and wanted. While justice must be done and crime does have consequences, we need a mayor who understands that enforcement and custody is not a long-term solution, and who is courageous enough to seek lasting change in a different way before more lives are lost.

Please don't forget the grieving.

Like all of us, children and young people only really listen to those they trust and trust is only found through a consistent and long-term relationship. Sometimes, for a host of reasons, they don't find that relationship at home. Many wonderful people work in our statutory services, but the services are either overwhelmed or not structured to facilitate providing such long-term trusted relationships. Also, sadly, many young people in desperate need, have not yet suffered a crisis worthy of statutory intervention, and so are invisible to system. Yet it is these 'invisible' young people, and those facing the toughest challenges, that are most in need of such a relationship.

One of our most successful projects has been community mentoring focussed on those who are most in need. It's life-changing when a member of a young person's own community, who is trained, supported and supervised by XLP, becomes 'that one person', as Cherry, Shayleigh, Tex, and Sephton will testify.

It's all too easy to focus mentoring help on those who are 'just below the line' or already exhibiting prestigious business potential, but what will you do to ensure that long-term mentoring relationships are accessible to those desperate ones who are at the bottom?

Please don't forget the invisible.

I don't pretend that all this will be easy. You will have some difficult choices to make. What I can tell you is that if you don't forget the unemployed, the lonely, the grieving or the invisible children and young people, then there are those of us who have been working in this city's communities for many decades before your election, and will be doing the same for many years after you have moved on, who will gladly work alongside you.

Please don't forget them.

Yours sincerely,

Patrick Regan OBE, CEO and founder of XLP