Migrant workers are essential to the Northern Ireland economy and enrich life in the region, a public rally against racism was told today.

Trade union leaders organised the protest in the centre of Belfast to speak out against a spate of racist attacks in the city.

Over 100 Romanians were forced from their homes in the most notorious recent incident, but the rally heard condemnations of "soft racism" which it was claimed feeds the actions of a violent minority.

Irish Congress of Trade Unions (Ictu) assistant general secretary Peter Bunting hit out at those who said they opposed racist attacks, but who always added the word "but".

"These are the remarks you hear on radio phone-in shows. 'I condemn this, but ...'," he said.

"This is soft racism. This is racism crossed with cowardice. People without conviction accusing others of evil.

"The facts cannot be clearer, in research report after research report.

"Migrant workers are not taking our jobs. Migrant workers are not taking our benefits. Migrant workers are not taking our social housing.

"In fact, migrant workers are filling jobs which need to be done, and paying taxes which pay for public services. They are collecting far fewer benefits than they are entitled to, such as universal child benefit.

"Migrant workers are young, and highly productive workers and are having children among a general population which is getting older. The children of migrant workers are reversing plans to close schools in certain areas.

"The health service could not function without skilled immigrant labour. Our most vulnerable, our aged and our ill, are being cared for by migrants.

"We owe them."

Several hundred people attended the event, despite poor weather conditions.

Mr Bunting told the audience outside Belfast City Hall: "This event today ought to be the launch-pad for a new campaign for sufficient resources for anti-racism champions in every community, across the creeds and the classes."

Threats were made this week against Polish and Islamic centres in Belfast.

More than 100 Romanians were forced from their homes in the city last month in an incident that attracted widespread condemnation.

Polish families in Co Tyrone were attacked, as was an Indian centre in Belfast.

Police have said the spate of attacks was not co-ordinated, but the increased attention on the issue sparked an Assembly debate on racism on Monday at which the violence against minorities was widely condemned.

Police have also warned Alliance party politician Anna Lo - the only member of the Northern Ireland Assembly from an ethnic minority background - that she was also under threat.