A group of lawmakers in the UK, US and Canada have launched a coordinated effort to urge the world’s richest countries to adopt sanctions targeting the allies of Russian President Vladimir Putin.

The group is demanding that leaders of all G7 nations adopt legislation similar to the US Magnitsky Act, which permits authorities to seize assets — including bank accounts and real estate — and ban the entry of Russians implicated in the death of Russian lawyer Sergei Magnitsky in 2009.