How much did he sell Chelsea for and hasn't he got any property in London to sequester. I suspect a rumble by HMRC might be in order. The Customs branch has more powers I believe, that the IR branch to size things and hold them....

The Chelsea sale money is frozen, also a scandal:

"Following Russia's full-scale invasion of Ukraine, the British government allowed Roman Abramovich to sell Chelsea FC to Todd Boehly. It did so on the condition that £2.5bn from the proceeds would be donated to charities supporting victims of the war in Ukraine.

Nearly three years later, the money still sits in a frozen Barclays bank account, reportedly due to disagreement over how it should be spent, with Mr Abramovich wanting the money to go to "all the victims" of the war, and the UK government insisting it should be spent solely on humanitarian aid in Ukraine."

https://www.bbc.co.uk/news/articles/cgrnqvqek4ro

It’s so much easier to go after the small fry than the big fish

Easier to punch down at people who cannot defend themselves, doesn't do a thing overall but is a show of strength of power and control to those on the receiving end of the outsized retribution.

"We won't go after tax evaders as we might mess with the wrong person if we do but we will go after the teeny fraction of fraud in benefits, might even spend more than we save but it's just because then all benefit recipients know they live solely at our behest and can take that away in moments."

Even though it was a Tory concept, Labour is still looking to allow the DWP to be able to search and seize people's property and let AI nosy around in people's private bank accounts for excuses to sanction or stop benefits. Don't really see the same rigours applied to tax evaders do you?