Ina a related video, an animated history of the European Union IBTimes UK

A leading race equality campaigner has urged both sides of the EU referendum to drop their "negative" rhetoric around the issue of immigration. Simon Woolley told IBTimes UK that it was a legitimate debating matter, but warned some of the language had turned ugly in the run-up to the 23 June ballot.

"There's been a lot of negativity on both sides, perhaps more with 'Leave' than 'Remain' about 'those foreigners taking our jobs'," the Operation Black Vote (OBV) director said. "If you are a Turkish man or woman or of Turkish decent living in the UK, you would feel pretty wretched about yourself with the really antagonist rhetoric about Turkish people at the moment."

Woolley's comments coincide with the launch of OBV's latest campaign to get more black and minority ethnic (BME) voters engaged with the referendum.

The non-partisan organisation said the four million BME voters in the UK could make the difference between a 'leave' or 'remain' result.

"The talk has been angry, it's often hostile towards black and ethnic minority communities, more broadly to foreigners in general. So we're being talked about, not talked with," Woolley added. "We are seeking to say 'look, this is a seriously contested debate, there are potentially four million BME voters and in that close fight we could be the balance of power."

OBV has teamed up with advertising firm Saatchi & Saatchi to launch a campaign targeted at BME voters. The poster is part of OBV's national consultation with the BME community on the subject of Europe, which will include a series of nationwide events and debates on the referendum.

The issue of immigration has consistently topped Ipsos MORI's concerns index, with latest survey conducted in April putting it two points ahead of NHS/hospitals and 11 points ahead of the EU (41%, 39% and 30%).

Ukip and Vote Leave have argued the UK's net migration levels would fall if Britain broke away from Brussels, while pro-EU Prime Minister David Cameron has previously promised to cut numbers down to "tens of thousands".

The latest official figures showed net migration had climbed to a record high of more than 323,000 in the year to September. The Office for National Statistics (ONS) explained that immigration to the UK had hit 617,000 over the same period, while emigration away from Britain had fallen to 294,000.

Operation Black Vote poster
Saatchi & Saatchi