Today, on the International Day for Street Children, we in Europe must acknowledge that we have a problem - a known unknown - of a rising number of young and vulnerable people who need protection.
The vast majority of Europeans see street children as a faraway problem that they hear about on the news or witness for themselves on holidays to nations in the developing world.
The EU's political impotence in the face of the migration emergency means that this is no longer the case: thousands of street children are now sleeping rough on doorsteps from Athens to Paris.
At least 95,000 unaccompanied children applied for asylum in Europe last year, four times the numbers for 2014, and 10,000 cannot be traced by the authorities because they have fallen either into the hands of criminal gangs or onto the streets and into the informal economy.
Like in the developing world, street children in Europe go uncounted and they are left off international and national policy agendas, leaving it up to low-resourced NGOs and volunteer organisations to pick up the slack.
These children have no voice, no lobby and no protection from those who wish to take advantage of them.
At the international level, the UN is doing its part. Next week street children from across Europe will make their voices heard and influence policy makers by feeding into the UN Committee on the Rights of the Child's 'general comment' on street children. The General Comment will provide authoritative guidance to States on how they can implement the UN Convention on the Rights of the Child for street children to ensure that their rights are protected and promoted.
But more needs to be done at the national and local level, particularly in Greece which is bearing the biggest burden amid a refusal by national governments within the EU to work on a sustainable relocation mechanism to take the pressure of periphery states where refugees are arriving from Africa and the Middle East.
Greece urgently needs capacity building for both its asylum and child protection systems. Officials there complain Europe promises money and manpower but it has yet to arrive.
It is also vital Europe works together to implement its relocation programme and to set up safe and legal routes to ensure unaccompanied children can make it to their destination.
The consequences of not doing so are unacceptable. Unaccompanied children, or children who get separated from their families en route to Europe, if prevented from crossing into Macedonia are sent to children's centres in Thessaloniki and Athens. Sending children to a centre, where they are less publicly visible does not remove their desire to reach their destination. Many of these children are disappearing onto the streets, where they become vulnerable to challenges that street children face anywhere in the world - violence, exploitation and hunger.
It is a scandal that in January, David Cameron has rejected calls for Britain to take 3,000 unaccompanied child refugees from Europe. If Europe's lost children cannot galvanise a sustainable response to the continent's migration emergency, what will? Britain and the other nations in Europe opting for inaction over refugees must put aside the petty and selfish politics of xenophobia and nostalgia and take action proportionate to the scale of the crisis.
Diane Abbott is the shadow international development secretary and Labour MP for Hackney North