Ian Katz
Newsnight Editor

A few quick takeaways from tonight’s immigration debate:

1. Whatever the academic truth about the impact of immigration on Britain is, this is the issue that more than any other in this campaign excites real passion. And in a place like Boston there are many with direct experience of its costs as well as its benefits. Some of the most striking contributions tonight were from members of the panel and audience talking about the effect of high levels of immigration on NHS services, and wages.
2. Even defenders of free movement within Europe are reluctant to defend the idea of a Britain with a population of 80 million – the ONS’s projection for 2060 on current trends. When Evan challenged Remain advocate David Hanson on this, he preferred to argue that the population would never reach those levels.
3. There is still no settled view within the Leave camp about what Out looks like. Michael Gove this weekend insisted our future would lie outside the single market. But Kwasi Kwarteng, arguing for Leave tonight, thought the UK’s post-Brexit status remained a matter for negotiation.
4. When this campaign is over, a lot of Conservative MPs will have said a lot of distinctly unhelpful things about the Tories’ record in government. Tonight it was Kwasi Kwarteng, dissing the government’s record on immigration: “That was a clear manifesto commitment that we haven’t reached.”

There was a direct clash of views between two of our experts.

Jonathan Portes from the National Institute of Economic and Social Research spoke about the cost "benefits" of having migrants here – as opposed to them being a drain on the welfare state: 

But Harriet Sergeant from the Centre For Policy Studies strongly disagreed:

Then another clash – this time on the number of migrants entering the country...

Harriet Sergeant said:

 Which David Hanson MP took issue with...

Then Evan put pro-Brexiteer Kwasi Kwarteng on the spot. Would he accept a single market without restrictions on freedom of movement? Mr Kwarteng replied:

David Hanson MP said it was worthwhile to accept freedom of movement and explained why:

We also heard from the audience on EU migration. Caroline, headteacher of a school in Grantham, said:

... But local business owner Darren Bevan didn't agree. He said EU migration has helped his business stay competitive.

"The effect of migration has been a very positive one."

Here's how the programme started... with Angie Cook, a local business owner - who is not happy about the level of migration in Boston.

She says her business has been ruined.

Image source, Science Photo Library

What do some of our undecided voters think after watching the show at home – have their views on migration changed?

Padraig Stapleton says his views were strengthened by the discussion:

Michelle Joseph Brown also thinks her stance was confirmed by the guests' views:

One of our guests tonight was Boston GP Dr Rohini Deshmukh. She told us they are struggling to cope with numbers – but it would be "unethical" to turn people away from registering. 

Image source, Getty Images

Migration isn’t just a one-way street, you know. Lots of Brits live on the continent. But how many, exactly?

Lots of politicians like to quote the number of UK citizens living and working in other EU countries at two million – Nicola Sturgeon was at it just the other month.

The figures are based on research by the Institute of Public Policy Research (IPPR) think tank in 2010, which put the number between 1.8 and 2.2 million.

But wonk wars broke out in 2014 when research by the Migration Observatory at Oxford University – based on the newly-published Census – estimated just 1.1 million UK-born people were living on the continent in 2011.

The biggest battalions of Brits (is that the right collective noun?) are to be found in Spain and in Ireland. In 2014 there were 314,421 and 233,248 UK citizens residing there respectively, according to Eurostat.

The DWP compiles a list of pensioners living in the EU – to check the latest figures country by country, click here, external.

For more EU fact checking, head over to our colleagues at BBC Reality Check.

What do you think? We're now off air but the debate continues online. Get involved using #newsnight

Image source, Getty Images

Can any Tom, Dick or Harriet enter the UK at will if they have a passport from an EU member state?

Well, no. The Government has the authority to stop EU immigrants from entering the UK if they fall foul of certain specific criteria.

The Home Office say that, since 2010, more than 6,500 EU nationals had been denied entry. Last year, 2,165 EU passengers were turned away.

Entry can be blocked on grounds of public policy, public security or public health, according to EU rules, though any EU national denied entry must represent a “genuine, present and sufficiently serious threat affecting one of the fundamental interests in society”.

Just having a plain old criminal conviction does not constitute grounds for refusal.

And to put the 6,500 figure in context, in just one year (2014 – the latest available) about 35 million EEA and Swiss passengers, excluding Brits, presented themselves at our border controls.

For more EU fact checking, head over to our colleagues at BBC Reality Check.

Which David Hanson MP took issue with...