Concern about immigration has reached record heights after a summer of chaos across Europe, a poll reveals.

Some 56 per cent of the public say shoring up our porous borders is among the most crucial issues facing the UK – a six point rise in a month.

Some 40 per cent believe it is the single biggest concern – dwarfing the NHS, which was in second place on 9 per cent.

Some 56 per cent of people say immigration is one of the major issues facing the country, well ahead of the NHS on 36 per cent

The under-25s are the least bothered about immigration, with levels of concern rising with age to hit 65 per cent among the over 65s

The survey by Ipsos MORI followed a dramatic summer involving the crisis at Calais, the unprecedented influx into Europe of refugees fleeing war and poverty, and net migration into the UK at a record high.

It came as fresh splits over immigration erupted within Labour. Leader Jeremy Corbyn insisted the influx of hundreds of thousands of migrants to Britain each year was ‘nothing but a plus’. But hours later shadow Home Secretary Andy Burnham later warned the party was ‘out of touch’ on migration and called for a tougher line to win back supporters who fled to Ukip.

The poll, published yesterday, found that concern over immigration was the highest for any issue since 2012 – when 56 per cent of people expressed worries about the economy. Three-quarters of Conservative voters listed immigration among the most significant issues, as did almost half (49 per cent) of Labour supporters.

Of those aged 65 and over, immigration was a significant issue for 64 per cent and it was the biggest concern in all parts of the UK except London.

See the latest news, pictures and updates on Europe's migrant and refugee crisis

A young girl shelters along with dozens of others at a refugee camp at the Greece Macedonia border

Last night Lord Green of Deddington, chairman of the think-tank MigrationWatch, said: ‘These are extraordinary figures.

‘They are yet further evidence of the common sense of the British people. Not only is our population increasing at the fastest rate for nearly a century, but public services are coming under enormous strain and in parts of our country, society is changing far more rapidly than many people wish to see.’

Tory MP Peter Bone said: ‘In Middle England it is absolutely the number one issue by a country mile. They are not concerned about immigration from the Commonwealth and sub-continent but unlimited EU immigration. The issue is the sheer numbers. GP surgeries, schools and health services are all under pressure, overcrowded and really struggling.’

Hundreds of migrants queue at 'The Jungle', a campsite for migrants in Calais. Immigration is one of the more crucial issues to currently concern the UK public

Ukip’s immigration spokesman Steven Woolfe said: ‘This poll number reflects badly on those amongst our country’s leaders who do not see how mass uncontrolled immigration is damaging the fabric of our nation.

‘The people of this country do because they have the common sense to see that mass migration changes nations.’

Bobby Duffy, of Ipsos MORI’s social research institute, said: ‘This represents the highest level of concern we have ever recorded about immigration – as the focus has shifted away from the refugee camps in Calais to the movement of people across Europe.’

Ipsos MORI, which carried out its Issues Index for The Economist, regularly asks voters what they think are the most important factors affecting Britain today.