I think these people have a right to enter other countries seeking better lives for themselves and their families. However, I think that those who are allowed into the country should undergo a full health check to ensure that nobody with TB, HIV etc. is allowed entry into the UK. Furthermore, it would be nice if these people had qualifications which would benefit the UK. But, this would be a problem as there aren't really any decent schools/colleges in these poor countires, perhaps the richer countries could work together to produce a foreign schooling system in the 3rd world that will provide people with a chance to get a degree, provided that once they have completed the course, they must come to work in one of the richer countries. This way, they would easily pay off the debt that the richer countries pay to build and maintain these schools by using their learned knowledge to work in the richer countries. A chance like that would be extremely appealing to these poor people and I think it could be a huge success.
Just an idea.