Former US presidential hopeful Bernie Sanders has taken a break from battling Donald Trump to endorse his brother Larry, who is looking to replace David Cameron as MP in Witney, Oxfordshire, in a by-election to be held on 20 October.

Larry Sanders, an Oxford-based local councillor, has lived in the UK since 1969, and spent eight years as leader of the county council's Green group. The 82-year-old will campaign on an anti-NHS privatisation platform and his brother recorded a heartfelt campaign video aimed at voters in the constituency released on Tuesday 11 October.

At 75-years-old, Bernie is the younger of the two siblings but he took time away from backing Democratic nominee Hillary Clinton to support his older brother, who is contesting the empty seat left by Cameron on 24 September 2016 as a Green Party candidate.

Bernie, the Vermont senator, started the video by saying "that I do not know a heck of a lot about British politics" but said his brother had a "very strong influence over my life".

The 75-year-old said: "From when I was a very little kid, Larry and I discussed issues of social justice, economic justice, and racial justice. And what I can tell you is that my brother is a very, very caring human being, who wants to see government represent all of the people, not just the people on top."

Sanders Clinton
Sen. Bernie Sanders has backed his brother Larry a Green Party candidate Justin Sullivan/ Getty Images

The Brooklyn-born politician added: "He wants to see a society in which we do not have massive levels of income and wealth inequality, wants to see a society where healthcare is a right of people and that means quality healthcare under the national health system.

"For decades now, and I hear this from him almost every week, he has been working to strengthen the NHS to ensure that it is the quality system that everyone in the UK is entitled to."

Larry Sanders
Bernie Sanders' brother, Larry, will contest the Witney by-election Green Party

Despite the former British prime minister saying he would stay on as representative for the Witney constituency, he later felt that his presence would be a distraction as the UK wrestles with the Brexit fallout. The Conservatives have selected Robert Courts, a 37-year-old barrister, as the party's candidate, but the seat will be hotly contested by Larry, who is the Green's spokesman on health matters.

Cameron won just over 60% of the vote in the 2015 general election but this time round the Liberal Democrats hope former deputy prime minister Nick Clegg can influence the local electorate campaigning with their candidate, Liz Leffman.

Labour have selected Oxfordshire councillor Duncan Enright while the English Democrats have unveiled former Ukip activist and Celebrity Big Brother contestant Winston McKenzie as their parliamentary hopeful.

Larry said when he was selected: "The major political parties are in disarray. The policies of the last 30 years, shifting resources and power from the majority to the richest, culminated in the illegality and greed which crashed the economy in 2008.

"The Green Party has pledged to make Britain a fairer and less divided nation. We need to show that we don't want Britain to be the most unequal country in Europe. We don't want unmet health needs to increase when we already have too few doctors, nurses, and hospital beds.

"We don't want the government to impose unworkable contracts on 50,000 precious doctors, when it is clear that the supposed reason for the contract, a seven day hospital service, can't be done at present funding."