As has been widely reported, the Home Office has decided to exclude the controversial Dutch MP Geert Wilders from the UK; here’s the letter it sent him notifying the decision. Many people will be troubled by this: there has already been criticism of his exclusion from Melanie Phillips and Daniel Hannan, and no doubt there will be more. I’m troubled, too.

I want to focus on lawfulness of the decision, though. Wilders has been excluded under regulations 19(1) and 21 of the Immigration (European Economic Area) Regulations 2006, which faithfully copy out and implement the requirements of article 27 of Directive 2004/38 on the rights of EU citizens to move freely. For those interested, I last wrote about the Directive when Learco Chindamo won his fight against deportation in 2007.

Both the regulations and the Directive make clear that an EU citizen can only be excluded on grounds of public policy or security if his conduct represents

a genuine, present and sufficiently serious threat affecting one of the fundamental interests of society

(see regulation 21(5)(c) of the Regulations, and article 27.2 of the Directive); and, crucially, both pieces of legislation expressly require that the decision must (see regulation 21(5)(b) and article 27.2)

be based exclusively on the personal conduct of the person concerned

But was this decision based exclusively on Wilders’s personal conduct? The letter says his presence in the UK – not his likely conduct – would threaten “community harmony”. The clear implication is that Wilders’s prsence might attract violent demonstrations from others, presumably those offended by him and his film, Fitna. But that’s about the likely conduct of others; not Wilders’s personal conduct. The weasel words of the Home Office suggest Wilders’s past conduct, i.e. his statements about Islam, is the source of the risk but this cannot be right or sufficient – his statements in themselves, considering them exclusively and without reference to any reaction, do not threaten anything.

In my view the letter is badly reasoned both because it fails to explain why Wilders’s conduct is considered a threat – it reads as simply asserting that his past statements “would be” a threat – and because it is elliptical about what must be a key factor motivating the decision.

Even if it’s lawful under the regulation and Directive to take account of the possibly violent conduct of others – which must be doubtful – it cannot be proportionate, as required by both pieces of legislation (see regulation 21(5)(a) and, again, article 27.2), to conclude in the abstract, in advance and without first trying reasonable security measures that Wilders’s conduct will cause reactions that threaten community harmony.

If that weren’t enough, the UK is bound to respect Wilders’s freedom of expression not only under the Human Rights Act but as a matter of EU law in applying the Directive, and particularly bearing that in mind, in addition to Wilders’s free movement rights, this prior exclusion must be disproportionate.

It’s going to be very interesting to see what happens when Geert Wilders lands at Heathrow, as he says he’s still intending to do – and to see what happens when he appeals to the Asylum and Immigration Appeals Tribunal.