A hunger strike by hundreds of migrants living in Belgium without legal permission is putting increasing pressure on a government coalition weighing the wellbeing of those involved against the need to stick to immigration and asylum rules.

The hunger strike started over a month ago in two universities and a Brussels church, by migrants desperate to obtain legal residency papers to continue and improve their lives in a nation where some say they have been working and living for a decade.

To highlight their desperation, some hunger strikers stitched their lips together this week, and are only accepting small amounts of liquids through a straw. Estimates of the number participating range as high as 400 but Migration and Asylum State Secretary Sammy Mahdi has used a figure of about 200.

Mahdi has insisted he is seeking to quicken up and improve the whole application system for people seeking to stay in Belgium but refuses to budge when facing demands by the hunger strikers for their cases to be handled now.