British-based American Democrat voters are a "secret weapon" in the drive to keep Donald Trump out of the Oval Office, UK campaigners say.
With under a week until the US decides who should be the next president, Democrats Abroad UK (DAUK) is stressing it is not too late for Americans to register to vote.
From its central London campaign office the group is calling on US citizens based in Britain to make sure "every vote counts" in the White House race, which reaches a climax on November 8.
DAUK chairman Robert Ravelli, who moved to Britain nine years ago, said: "We want to make sure we get every single vote we can possibly get in the UK.
"We will be spending a lot of time between now and Tuesday to do so."
DAUK said it estimates there are around 200,000 - 250,000 Americans who currently live in the UK and are eligible to vote by absentee ballot.
Americans living overseas typically register to vote and return their ballot to the state where they last lived - each state has its own deadlines and processes for this.
An army of around 125 volunteers are currently spending their time calling voters and assisting them with the registration and ballot process.
Deputy chairman of DAUK Inge Kjemtrup said more Americans had been found who may have been in the country a long time and not voted before, and want to have their say in the election.
"I think this election has been a huge motivator for people," she told the Press Association. "Donald Trump has been our best recruiting agent."
A poll on Tuesday showed the Republican candidate one point ahead of Democrat presidential candidate Hillary Clinton, which Mr Ravelli dismissed as a "snapshot in time", and said it was the "electoral votes that count".
Former DAUK deputy chairman Karin Robinson said: "Democrats Abroad are a little secret weapon that we have to offer because we do not show up in polls.
"Where those absentee ballots do come in we can be an undetected blip on the radar of the election outcome.
"We know that overseas ballots have made the difference in past elections. In 2008 it probably swung North Carolina for President Obama."
Mr Ravelli said: "It is very important, especially in some of these states which have tight races in the congressional races, that the absentee ballots be counted and sent it.
"It is also a way for the Americans over here to have their voices heard back home and it gets them involved - it is easy to feel very distant here when you are so far away."
DAUK said its aim is to see Mrs Clinton elected along with a Democrat House of Representatives and Senate, and that the gains the party had made in the last eight years were carried on.
"Donald Trump is a very, very, very flawed human being with no government experience," Ms Robinson said.
"Our dream is to not just win the election - winning the election is the necessary but not the sufficient condition.
"We want to win by enough to send a clear signal that this is not who the American population is, is not who we are as a nation.
"That some of these extreme views that are being expressed do not represent the increasingly diverse, increasingly liberalising American population."
:: For more information on absentee voting visit www.votefromabroad.org.