Jeremy Corbyn has defended EU immigration, urging voters to instead direct their anger towards Conservative austerity measures.
The Labour leader said pressure on infrastructure would not disappear in the wake of a Brexit, blaming the EU for lowering living standards across the rest of Europe.
After criticisms that Labour has done little to address immigration concerns among voters, particularly in the north of England, Mr Corbyn also complained that the far right have been allowed to lead the debate.
Asked if there can be an upper limit for immigration, Mr Corbyn told the BBC's Andrew Marr show: "I don't think you can have one while you have the free movement of labour.
"I think the free movement of labour means you have to balance the economy so you have to improve living standards and conditions and so that means the European Union's appalling treatment of Greece, particularly the European Central Bank as well as the European Union, that is a problem.
"f you actually deliberately lower living standards and increase poverty in certain countries in south-east and eastern Europe then you're bound to have a flow of people looking for somewhere else to go.
"Surely the issue is an anti-austerity, a growth package all across Europe rather than this."
In an attempt to address voters' concerns, he hailed an intervention by former archbishop of Canterbury Dr Rowan Williams who criticised "unfounded" claims that the UK is "full".
Mr Corbyn said: "The far right have been able to grasp the agenda. (Nigel) Farage for example puts up that appalling poster which has a picture of a lot of desperate people fleeing from war saying, they're coming to threaten us.
"Hello, I think Rowan Williams called it absolutely right when he said we have to play our part when dealing with the refugee crisis.
"It's a failure of our Government to properly fund local authorities, it's a failure of our Government to provide housing for people, it's a failure of our Government for the first time in 20 or 30 years maybe attacking school budgets.
"It's that that is the problem and they should turn their anger towards the Government and the austerity that's been put forward by Cameron and Osborne over the past six years."
But leaving the EU on Thursday would make it "very much more difficult" to tackle the impact of immigration because of a predicted shock to the economy.
He said: "If we leave as a country exactly the same arguments are going to be made about housing, about jobs about social security, all those issues are going to be exactly the same on Friday as they are on Thursday.
"The only thing is it's going to be slightly more difficult, or very much more difficult, because the trade arrangements with Europe are now quite deeply embedded.
"A very large number of jobs in Britain do depend on jobs in Europe. People should think very, very carefully about the direction in which were going.
"Let's not turn our back on the humanitarian crises existing around Europe."