Afghan refugee were not allowed to land in Australia

"There are methods of travel available now that didn't exist in the past to the same extent," he said.

Ilunga Ngandu, Regional Director of the United Nations High Commission for Refugees for Southern Africa, said the growth of global communications and culture made the idea of travel more attractive than before.

He said: "if you are sitting in a slum every day, you can still see through the media how richer people are leading their lives in other countries."

If the rich countries spent more money on poverty alleviation, and less on immigration policies, they might achieve results

UNHCR regional director Ilunga Ngandu

And if people cannot get to Europe or North American through legal channels, they will use other methods instead.

At the same time, experts warn that smugglers who specialise in trafficking asylum-seekers or economic migrants are becoming increasingly sophisticated, and increasingly willing to use dangerous methods.

All this suggests that the pressure on richer countries is bound to increase, regardless of the immigration policies they adopt.

And with more desperate people willing to take risks in order to travel, the dangers increase.

Iraqi Kurds in southern France

Mr Moraes added: "After all, smugglers are not there to help asylum-seekers, they are looking to make money."

He said that improved police intelligence and co-operation between countries was not enough by itself.

European countries needed to combine policies on burden-sharing so that when a crisis flared up in a certain region, various countries agreed to absorb refugees.

But ultimately it is a problem that might best be tackled at the point of departure.

Ilunga Ngandu of the UNHCR said: "If the rich countries spent more money on poverty alleviation, and less on immigration policies, they might achieve results."

Claude Moraes agreed: "Improving conditions in asylum-seeking countries will obviously take a long time but it would be a good start."

Asylum seekers in Glasgow have suffered from racism

Both men point out that contrary to popular belief in the developed world, it is the poorer countries which receive the greatest numbers of economic migrants and asylum-seekers.

People will tend to move first to the nearest relatively prosperous and stable country.

Mr Ngandu said: "For example, South Africa is a magnet for people from all over Africa, because they believe there are such great opportunities here."