LONDON: Campaigners for Britain to leave the European Union in next month’s referendum warned that immigration from the bloc had “spun out of control” as new figures showed net migration at its second highest ever level.

Exactly four weeks before the June 23 vote, the Office for National Statistics (ONS) published data putting net migration at 333,000 in 2015, the second highest figure on record. Net migration is the difference between the number of people coming to the UK for at least a year and those leaving.

The record of 336,000 was set in June last year. A total of 270,000 EU citizens came to Britain in 2015, up 6,000, and net EU migration was up 10,000 at 184,000.

New data from the Labour Force Survey found 2.1 million EU nationals were working in Britain between January and March 2016, up 224,000 on the same period last year.

“We must face the fact that the system has spun out of control,” said Brexit campaigner Boris Johnson, the former London mayor and a possible successor to Prime Minister David Cameron, in a statement.

“We cannot control the numbers. We cannot control the terms on which people come and how we remove those who abuse our hospitality. This puts huge pressure on schools, hospitals and housing.”

He said Britain had benefited from immigration but it had to be limited, and said that staying in the EU meant “kissing goodbye permanently to control of immigration.”

UK Independence Party (UKIP) leader Nigel Farage tweeted: “Mass immigration still hopelessly out of control and set to get worse if we Remain in EU.”

Many Europeans are drawn to Britain because of its relatively strong economy, and under EU rules of freedom of movement, the government cannot stop them.

Brexit supporters have put ending this freedom of movement at the heart of their campaign for a “Leave” vote.

Immigration minister James Brokenshire said the number of people moving to Britain “remains too high” but said that leaving the EU was “no panacea or silver bullet.”

He said the government had cut abuse of the student and family visa schemes for non-EU migrants, and would soon introduce new laws on tackling illegal employment.

Reforms to welfare payments to EU citizens, secured by Cameron in February, would also have an impact, he said.

New mayor of London Sadiq Khan, the son of Pakistani immigrants, said EU citizens working in Britain brought in billions of pounds in taxes.