The head of a UN agency has fiercely defended the role of migrant workers in Europe, describing them as an “underestimated and under-appreciated” force that strengthens local economies and is not a threat to the jobs market.

As political debate rages in many European countries over the influx of tens of thousands of refugees from the Middle East and north Africa, Kanayo Nwanze, the president of the Rome-based International Fund for Agricultural Development (Ifad), said migrant workers “contribute tremendously to the economy, increasing the economic output of Europe”.

His comments come ahead of the release of an Ifad report on remittances from migrants based in Europe, which found that only 20 per cent of earnings were wired back home, with the rest pumped into host economies. For 26 European countries, remittances represent an outflow of wealth — on average — of less than 0.7 per cent of their GDP, according to the report “Sending Money Home”.

Overall, 50m migrant workers resident in Europe sent $109.4bn abroad in 2014, up 19 per cent with from 2012. The top six European remittance sending countries — Russia, UK, Germany, France, Italy and Spain — account for 75 per cent of the flows.

“I don’t want to mix issues, but unfortunately because of the massive refugee influx, the resident migrants in Europe are being looked upon as a problem, and this is not the case,” Mr Nwanze said in an interview with the Financial Times.

He called on European governments to adopt more policies “that recognise the rights of migrants who are contributing to the country”. He also pointed to a rise xenophobia — in Italy and Europe as a whole — saying that many highly qualified, long-term migrant workers were also the victims of discrimination “because of the colour of their skin . . . until they pull out their ID card”.

Mr Nwanze addressed concerns often voiced by anti-immigrant parties such as Italy’s Northern League that migrants were “stealing” jobs at a time when unemployment was already very high.

“It is important to recognise that in Europe [migrant workers] are not competing for jobs with nationals but [they are] filling the gaps of the labour market,” by picking up jobs “that Europeans won’t do”, especially in the agriculture, construction and services sectors.

The Ifad report estimates that some 150m people worldwide benefit from remittances coming from Europe. Last year about one-third of the value of remittances stayed in the continent — in the Balkans, the Baltics and eastern Europe — and the remaining two-thirds went to more than 50 developing countries, north Africa and Central Asia being the most reliant regions.

The agency is working to push down the transfer cost of remittances — on average, 7.3 per cent in Europe — and to increase the sums invested in rural areas reliant on money sent from workers abroad.

“By reducing transfer costs to 5 per cent, as per the G20 objective set in 2009, an additional $2.5bn would be saved for migrant workers and their families back home,” Pedro De Vasconcelos, co-author of the report and co-ordinator of the Financing Facility for Remittances at IFAD said.