There cannot be many teachers who can walk into the staffroom and say they have influenced the course of their country's general election.
But Willem Richter, a 27-year-old secondary teacher, can do just that after securing a Constitutional Court victory in his native South Africa to allow expats like himself to vote in next month's ballot.
With the help of a political party in Pretoria, Mr Richter challenged a ruling that prevented those registered to vote in South Africa but living outside the country from taking part in the general election on April 22. On March 12, the court ruled the edict invalid and unconstitutional, paving the way for South Africans around the world to vote.
Mr Richter, who teaches maths and biology to 11 to 16-year-olds at St Mark's Academy in Mitcham, south London, said: "I'm South African and I plan to go back to my country in a year or so. So what happens there is important to me.
"The government makes decisions which will affect me when I go back, so I want a say in who the government is going to be.
"This decision gives me faith in my country and gives me optimism for the future."
Mr Richter has been living and teaching in south London for two years since he graduated from South Africa's North-West University.
Some 2 million South Africans have left the country in recent years to seek jobs abroad or to escape violent crime, with anything up to 1.5 million living in the UK. South Africans already registered as voters and living abroad will have until March 27 to tell the country's Independent Electoral Commission of their intention to vote.
Mr Richter was backed by the mainly white, right-wing Freedom Front Plus party in his legal challenge, which began in November. He corresponded by email and telephone while party representatives, backed by other opposition parties, represented him in court.
Political analysts say they stand to gain more from the court decision than the ruling African National Congress, headed by controversial Jacob Zuma. It garners most of its support among poor black people who still make up a large proportion of the electorate, while most of those who have left the country are skilled white professionals.
Despite the court victory, Mr Richter remained modest. "I'm not sure how many of my teaching colleagues know what's happened, or my pupils," he said. "I'd prefer to keep it a bit low key in school.
"But on the day I had a lot of missed calls. I've had lots of emails and (texts) from people thanking me for getting them a vote, and my Facebook page has been inundated.
"I think it was worth it - 100 per cent - and I've got a real sense of satisfaction. I've not decided who I'll vote for. I'm thinking about it; I'll have to read the party manifestos."