Labour leader Jeremy Corbyn called for Britain to join a pan-European effort to help ease the migrant crisis as he visited camps in northern France to see the squalid conditions people are living in after fleeing war, poverty and persecution.
Mr Corbyn headed to the Grande-Synthe Camp, near Dunkirk, and The Jungle in Calais where more than 7,000 people are sleeping rough amid the mud, wet and cold.
As he met men, women and children who have fled from countries including Syria, Iraq and Afghanistan, Mr Corbyn spoke of the "dreadful situation" they faced camped in the swamp-like conditions.
Surrounded by migrants and refugees, he said: "What I'm trying to achieve here is to understand the nature of the refugee crisis that's facing the whole of Europe.
"Ultimately we deal with the situation by dealing with the problem at its source, which are the wars and conflicts.
"Also, there are the human needs of people. We have got people here who have been here for months, if not longer than that, with no proper education, no access to doctors, no access to dentists, limited access to food - in very cold, very wet conditions.
"These conditions are a disgrace anywhere. We as human beings have to reach out to fellow human beings."
Mr Corbyn said Britain should be part of a pan-European effort to help the people affected by the crisis.
He said: "Germany has done an enormous amount, other countries have done varying amounts and I think we should be part of bringing European-wide support to people."
The numbers of migrants and refugees at Grande-Synthe have steadily risen since last October, from around 800 people sleeping rough there to around 2,500 in recent weeks.
Most are Kurds from Iran, Syria and Iraq looking to cross to the UK, including some 250 children, according to Medecins Sans Frontieres.
Among those he met was 15-year-old Rekar Baber from Iraq who gained Mr Corbyn's autograph from him along with a selfie.
Others included Bawand Mustafi who said before speaking to Mr Corbyn: "We are here because of the ridiculous politicians of the world.
"We are here to save our lives. Now we are here we don't know what to do."
MSF took action in the face of what it called a failure by the authorities to offer decent living conditions to the masses camped there in ankle-deep mud.
Aid workers said people have been living in ultra-thin tents surrounded by puddles of water and food, which has attracted rats, prompting regular extermination operations.
Help and donations, including food, clothing and tents, have come from volunteers who often arrive at weekends from the UK, Belgium, Germany and the Netherlands.