Asylum seekers were joined by children and union supporters

Among the marchers were people who had occupied a mosque and 11 churches to press their claim to a legal status and union members who supported them.

A draft law making it more difficult for immigrants to get work permits was being discussed by parliament.

The "sans-papiers", as they are known, want the authorities to abandon the plans and let them stay in Belgium.

The bill put forward by Interior Minister Patrick Dewael would set up an independent body to assess asylum claims and would ensure that claimants get a reply within 12 months, the French news agency AFP reports.

But the protesters say it does not set out clear criteria for the sans-papiers (without papers) to regularise their status.

Pieter de Gryse, from the Forum of Asylum and Migrations, said thousands of people had been living in Belgium for a number of years without papers.

"They have all kinds of links with Belgian society, they are very well integrated, they have family members here," he told Reuters television.

"You cannot ask such people to leave the country any more. Other people have been here for a very long time in procedures, asylum procedures, that is not their fault, it is the fault of the authorities that these procedures last so long."

Poor conditions

The protesters also called for Mr Dewael's resignation.

Immigrants occupying one church recently called off a hunger strike

One asylum seeker taking part in the occupation of a church in Ghent told the BBC: "I want them to accept my documents.

"It is not normal to sleep here with my husband and my children. I want them to accept my papers so I can work."

Daniel Kokombo, spokesman for the sans-papiers, said the conditions for those seeking sanctuary in the holy buildings were horrible.

Solidarity

In one church there is a kitchen, a rota for showers and mattresses are dragged out at night for people to sleep on.

"If the minister gives us asylum today or tomorrow we will leave it because we cannot live here," said Mr Kokombo.

Immigrants occupying one church recently called off a hunger strike they were holding in protest.

Some individual pastors are sympathetic to the occupations, but the Church hierarchy says it is as much a political issue as a human one.

Eric de Beukelaer, spokesman for the Belgium Bishops' Conference, says the Church is caught in the middle.

"We are in full solidarity with those who are staying for a long time in Belgium who are just waiting here without any security for themselves or their children," he said.