This month, the Home Office published a widely reported study on the impact of immigration. We were told it found that the presence of immigrants was likely to lead to longer waiting times at GP surgeries; to put pressure on the number of primary school places because migrants tend to have more children; and to "poor quality, overcrowded accommodation, inflated rents, exploitation by unscrupulous landlords..."
Analysis of exactly the same data could have led to a very different set of conclusions. Take longer waiting times at GP surgeries - that reflects the Government failure to adequately invest and manage the NHS and social services, as well as the disruption caused by the wholesale, top-down and un-mandated reorganisation of the heath service.
Pressure on primary school places - surely that's the result of a failure to adequately forward plan, exacerbated by the Education Secretary's ideological attachment to "free" schools, which has prevented resources being targeted where there's the most need?
Whilst a housing sector marked by poor quality, overcrowding and exploitation has its roots in Britain's longterm failure to build adequate housing, particularly social housing, and to regulate landlords or letting agents, to the point where protests against their abstractions are growing.
In short, it's clear: the Government is scape-goating immigrants as a way of distracting attention from its own catastrophic failings.
You might expect the Labour opposition to be taking a stand against the government's approach to immigration, as demonstrated in this report, but on the contrary, they are pandering to it. The Labour Party has not apologised for taking Britain into the Iraq War, has not apologised for failing to regulate the bankers, has not apologised for the fact that inequality rose during its 13 years in power - but it has apologised for its immigration policy while in government.
Let's start by setting the facts straight. It's very easy to succumb to Government and Labour rhetoric and the rightwing media,to think that immigration is one of Britain's chief problems. Or that immigration has entirely changed the face and culture of our nation.
A study out last week found that generally, Britons think 31 per cent of the population is made up of recent immigrants. In fact the figure is 13% - representing about 7.5 million people. Black and Asian people are perceived to make up 30 per cent of the population, when the figure is closer to 11 per cent.
Turning the lens around, about 5.5 million British people live in other countries around the globe. So the overall rate of exchange isn't that out of balance.
Secondly, it's important to acknowledge the contribution immigrants make to Britain. The NHS could not operate without immigrant workers. Our social care system and our education system depend significantly on immigrant workers.
If you measure this contribution in financial terms, there is a significant net benefit thanks to tax and national insurance contributions made by migrants. Overall, they make a net contribution to the UK economy of £3 billion. And because they are often young, healthy, and skilled, their use of public services is limited - much lower than that of the general population.
So where is this attack on immigrants originating from? Politically, the answer is clear - and it has a pint in one hand and a cigar in the other.
Recently, I had the "pleasure" of being on Question Time with UKIP leader Nigel Farage. He claimed there were 80,000 Romanians in Britain, and that the Metropolitan Police had arrested 30,000 Romanian in the last five years. This smear masquerading as fact has often been repeated - and is effective at making a point.
And yet the picture presented just doesn't stand up to scrutiny.
In fact, according to the Labour Force Survey, there are actually 102,000 Romanians in Britain. That's at one point in time, the end of 2012.
The arrest figures over five years are actually less than 28,000. What's more that's total arrests made, not numbers of individuals arrested. They undoubtedly include some tourists, not included in the resident figures, and some individuals arrested multiple times.
Arrests are not charges, are not convictions.
And, finally, we are talking over five years, so it's wrong to imply, as Mr Farage does, that the figure represents a significant proportion of the current Romanian population.
Whilst the figures around broadly accurate in each instance,their manner of assembly is deeply dishonest, deeply misleading, and deeply dangerous.
I was speaking today in the Romanian Cultural Institute - and I know that this portrayal has caused deep offence and worry in Romania. I can only apologise. And as an audience member pointed out, also Bulgaria.
In Britain today we are witnessing a "race to the bottom" on immigration rhetoric. Less than two in 10 of us think that immigration is a problem for our local area, and yet about three quarters are in favour of reducing immigration. That's the sad consequence of the vicious rhetoric.
We must acknowledge people's real concerns about standards of living; what the future holds for our children; the problems with housing supply, with public services; the threat posed by unemployment and low wages. But in doing so let's place the blame where it truly lies, not casually and cruelly point the finger at immigrants.
Only about one in ten new jobs goes to an immigrant. Our minimum wage, which should underpin a balanced labour market is inadequately enforced. It's also well below the living wage level at which it should be set. And whilst firms are being allowed to increasingly use zero-hours contracts and forced casualisation, no one can build a life on the jobs they offer. These are problems caused by bad labour market regulation and poor economic management, not immigration.
Yes, people, particularly in the South of England, can feel their communities are overcrowded. And travelling on the London Tube too often feels like I imagine a sardine in a can does. Yes, traffic congestion is a huge problem, as well as a huge threat to health. And yes, housing costs have inflated out of control.
But there are also a million empty homes in Britain, whole streets and even suburbs gutted by depopulation in the North of England.
The congestion felt in some parts of the country is caused not by immigration, but by regional development policy failing to spread prosperity across the whole of the UK.
And, as Green Party Leader, you won't be surprised to hear me express grave concern about Britain's environmental impact on the world. We're living a "three planet" lifestyle, when we only have one earth, so we urgently need to reduce our ecological footprint. But that's not a problem caused by immigration - and it's a challenge for the whole world, not just Britain.
All of these are urgent issues. None can be laid at the door of immigration.
And using immigration as a political football is a risky business.
It has real world, serious, even potentially deadly consequences. The declaring of open rhetorical season on migrants is a signal. It's a signal to the drunk man in the pub, who wants a target for his abusive tongue, and quite possibly his fists, and is now increasingly likely to find it in someone who is, or who he perceives to be, an immigrant. It's a signal to the irate woman on the overcrowded bus, ready to launch a tirade at a fellow passenger who might be an immigrant.
In 2011, Green Party conference chose to send a different kind of signal by passing a motion of opposition to the government's cap on immigration.
It said we should stop "treating those who are not native to the UK as a problem". Today, it's important to restate that.
We have a responsibility to say "enough". To acknowledge that we need to welcome immigrants, to remember that they are not economic pawns, but people, with families, with friends, with feelings - who deserve and are entitled to respect and respectful treatment.
This article is adapted from a speech given by Natalie Bennett at the International Symposium on Cultural Diplomacy today. The full version can be found here.
Follow Natalie Bennett on Twitter: www.twitter.com/@natalieben