Racial disparities in some European nations cannot be tackled if legacies of colonialism and slavery are ignored, a report by a EU-wide network of anti-racism groups said on Wednesday.

The "Europe's Original Sin" report analysed the historic use by six former colonial powers - Belgium, France, Germany, the Netherlands, Portugal and Spain - of policies and legislation that excluded racialised groups, and its lingering impact today.

The Brussels-based European Network Against Racism said those policies and exploitation of resources and labour contributed to the economic growth of former colonial powers and stopped Black people from accessing wealth.

In the Netherlands, which forcibly transported more than half a million Africans across the Atlantic, slavery was a lucrative venture. By 1770, activities related to slavery accounted for 5.2% of GDP, according to the report.

In Portugal, which trafficked nearly 6 million Africans, more than any other European nation, the impact of the empire on the economy reached a substantial level around 1800.

"In tracing the historical trajectories of colonisation, slavery and Europe's abuses, it becomes evident these deeply entrenched systems have left a lasting impact on the socio-economic landscape of Europe," the report said, adding many continue to face racial discrimination in education, employment, social and financial services.

In France, the poverty rate for people of African origin is 39.5%, more than twice that of people of European origin. The wage gap persists elsewhere too. Racism and discrimination also manifests in mortgage approval, financial profiling by banks and geographic exclusion, the report found.

Among several recommendations, the European Network Against Racism called for compulsory anti-racism training for financial and banking institutions, as well as for those responsible for designing and implementing social welfare policies.

"Understanding the colonial legacy is essential for crafting policies that address historical injustices," the report said.

It also said that any reparations for slavery and colonialism should acknowledge the direct connections between current economic conditions and past colonial exploitation. Schools' curricula should raise awareness of it as well.

The highly divisive issue of reparations to address historical wrongs is long-standing but has been gaining momentum, with several institutions such as the Church of England and some nations acknowledging their past.