MANCHESTER, England, Oct 6 – Mass immigration is damaging British society, interior minister Theresa May will say on Tuesday in a speech designed to ease some voters’ concerns that the government is failing to control the country’s borders.

May will tell the ruling Conservative Party’s annual conference that levels of immigration seen over the last 10 years were not in the national interest.

Net migration into Britain reached a high of 330,000 people in the year to March, far above the 100,000 level Prime Minister David Cameron has promised.

High rates of immigration has fuelled support for rival parties and is seen as a factor that may persuade Britons to vote to leave the European Union at a planned in/out referendum on the country’s membership by the end of 2017.

“When immigration is too high, when the pace of change is too fast, it’s impossible to build a cohesive society,” May will say according to local media reports.

She will say mass immigration strains public services like schools and hospitals and drives downs wages and pushes some people out of work.

(Reporting by William James, editing by Elizabeth Piper)