There is no such thing as an ‘illegal’ or ‘bogus’ asylum seeker. Under international law, anyone has the right to apply for asylum in any country that has signed the 1951 Convention and to remain there until the authorities have assessed their claim.
There is nothing in international law to say that refugees must claim asylum in the first country they reach. A European regulation allows a country such as the UK to return an adult asylum seeker to the first European country they reached. This means that countries on the edge of Europe have responsibility for a lot more asylum seekers than others. Some of the countries through which people travel to get to Europe are not safe places and many have not signed the Refugee Convention, meaning that people who remain there will not get international protection and be able to rebuild their lives.
The top ten refugee producing countries in 2015 all have poor human rights records or on-going conflict. Asylum seekers are fleeing from these conflicts and abuses, looking for safety. (UNHCR, 2014 Global Trends: World at War)
In 2014, worldwide, 34,000 children applied for asylum having arrived in the country of refuge alone, with no parent or guardian. 1,945 of these applications were made in the UK. Many of them come from Eritrea, which was recently condemned by the UN for gross human rights violations. (Report of the Commission of Inquiry on Human Rights in Eritrea, 2015)
Many refugees and asylum seekers hope to return home at some point in the future, if the situation in their country has improved.
The 1951 Refugee Convention guarantees everybody the right to apply for asylum. It has saved millions of lives. No country has ever withdrawn from it.