SOMETIMES voters choose politicians.

And sometimes politicians choose voters.

Take the coming referendum on membership of the European Union. David Cameron - as The Herald reported on Monday's front page - has decided to disenfranchise 1.5m EU migrants.

This might not be good news for the prime minister.

After all, this concession to the Eurosceptics - surely - can only make it harder for him to win his preferred Yes vote for a reformed EU.

But it is certainly not good news for those who have settled in the UK from other parts of the bloc.

Why? Because if you want successful migration - and you should - then you want migrants to feel a stake in their new home, including in its democratic process.

True, Mr Cameron has chosen very nearly the same Westminster electorate that has just put him back in to power.

Which sounds fair enough, unless you are a EU citizen who just voted in the Scottish independence referendum or for Holyrood.

Then you might start to think that the UK's pick and mix electoral roll is a bit barmy. Even Christian Allard, the SNP's MSP for north-east Scotland, isn't going to be able to vote in the EU referendum.

How come? Because he is French.

Now there those who don't think "foreigners" like Mr Allard should decide the future of Britain's place in Europe.

This isn't an entirely logical position. That is because the roll that Mr Cameron has picked for the EU referendum doesn't exclude all "foreigners"; it only excludes those who have, potentially, the most to lose from the UK quitting in the EU.

Citizens of, say, Zimbabwe or Malawi and all other Commonwealth states, can vote, provided they have the right paperwork. But those from, say, Belgium can't.

It gets even more confusing. Irish citizens - who are, officially, not considered foreigners in Britain - will get a say on EU membership. So will Maltese and Cypriots.

As will the people of Gibraltar - who can't vote in UK general elections. A Spaniard who has moved to Edinburgh won't get a say.

But an immigrant Scot on the Costa del Sol just might, provided he or she has been abroad for less than 15 years. Bizarre? Yup.

British politicians still talk of "foreigners" - despite the fact that F-word isn't as meaningful as they think, in rhetoric, or as the Irish example shows, reality.

Pro-Europeans aren't impressed by this kind of language. The European Movement in Scotland, appalled by the disenfranchising of EU migrants, has accused the UK Government of "narrow nationalism". They have a point.

How would the world have viewed Scotland if we had excluded migrants from the EU - or, somehow, even those from the rest of the UK - from our big vote last year?

The UK isn't the only place with eccentric and messy rules on who can and cannot vote and when. But supporters of the British state may wish to reflect on Mr Cameron denying the vote to EU citizens before they next accuse the SNP-led Holyrood of "narrow nationalism".