> Nothing to do with Brexit - as you said this has been getting more difficult for decades
Brexit has made it worse for UK citizens with non-UK spouses. When in the EU, the UK had to give residence permits to the non-EU spouses of EU citizens – except for its own citizens. So if an Irish citizen arrived in the UK with their American spouse, the UK had to give the American spouse a residency permit; however, if a UK citizen turned up with their American spouse, the UK was allowed to treat that American spouse as harshly as it liked.
But, the ECJ made some exceptions to that exception, which provided loopholes for UK citizens to get easy residency for their non-UK spouse. The first was the so-called "Surinder Singh Route", named for the 1992 ECJ judgement which established it – if a UK citizen and their non-EU spouse went and lived and worked in another EU country, e.g. in Dublin, for a reasonable period (never precisely defined, but 3 months was generally accepted as sufficient), then the UK had to give the non-EU spouse a residency permit on their return to the UK.
More recently, another ECJ judgement, the 2017 Lounes judgement, established that an EU citizen who moved to the UK, and then naturalised as a UK citizen, was to be evaluated under their non-UK EU citizenship when their spouse was applying for a residency permit – which meant some non-UK spouses could get residency permits under the liberal EU rules even without having to spend a period of residency elsewhere in the EU.
But, of course, Brexit has closed all these loopholes. So Brexit has made the situation objectively worse for non-UK spouses of UK citizens seeking permanent residency in the UK.
Brexit has made it worse for UK citizens with non-UK spouses. When in the EU, the UK had to give residence permits to the non-EU spouses of EU citizens – except for its own citizens. So if an Irish citizen arrived in the UK with their American spouse, the UK had to give the American spouse a residency permit; however, if a UK citizen turned up with their American spouse, the UK was allowed to treat that American spouse as harshly as it liked.
But, the ECJ made some exceptions to that exception, which provided loopholes for UK citizens to get easy residency for their non-UK spouse. The first was the so-called "Surinder Singh Route", named for the 1992 ECJ judgement which established it – if a UK citizen and their non-EU spouse went and lived and worked in another EU country, e.g. in Dublin, for a reasonable period (never precisely defined, but 3 months was generally accepted as sufficient), then the UK had to give the non-EU spouse a residency permit on their return to the UK.
More recently, another ECJ judgement, the 2017 Lounes judgement, established that an EU citizen who moved to the UK, and then naturalised as a UK citizen, was to be evaluated under their non-UK EU citizenship when their spouse was applying for a residency permit – which meant some non-UK spouses could get residency permits under the liberal EU rules even without having to spend a period of residency elsewhere in the EU.
But, of course, Brexit has closed all these loopholes. So Brexit has made the situation objectively worse for non-UK spouses of UK citizens seeking permanent residency in the UK.