How borders are drawn and enforced has far-reaching consequences, whether we live on either side of them or halfway across the world.

As the more left-wing choice, Bernie Sanders made a strong challenge to Hillary Clinton to be the Democrats’ US presidential nominee this year. His brother is also trying to make his mark for the Left—only across the pond.

Britain’s Green Party has chosen Larry Sanders—not the fictional TV chat-show host—as its candidate to succeed former prime minister David Cameron in the by-election for Witney and West Oxfordshire, which will be held on Oct. 20. It will be a tough ask—Cameron held the seat for 15 years before he stood down earlier this month as an MP; his Conservative Party has had the seat since 1974.

Bernie Sanders has credited his older brother with influencing much of his progressive political thought. “We didn’t have a whole lot of books in the house and it was my brother who actually introduced me to a lot of my ideas,” he has said.

“We’re incredibly similar although he’s better at expressing it,” Larry Sanders told the Telegraph in 2015.

Sanders, an 82-year-old retired social worker and transplanted New Yorker, has lived in the UK since 1969, and has been active in Green politics for the last 15 years. In the 2015 UK general election, he stood as the Green Party candidate in the nearby Oxford West and Abingdon constituency, coming fifth out of seven contenders.

Sanders was initially an active member of the Labour Party, but he shifted his allegiance after the party became, in his words, “feeble.” ”I noticed that in Oxford Labour councillors were voting with Conservatives, and the only person dissenting was a Green councillor,” he told the BBC in 2015.

The progressive Greens have struggled to win a groundswell of electoral support, although they have seen some success with younger voters. The party garnered a 3.8% share of the total votes at the 2015 general election. It currently has just one MP in the House of Commons.