More than 6,000 votes cast in a London constituency for the general election were missed off due to a “spreadsheet issue”.
Wandsworth Council has apologised after revealing it had mistakenly failed to include 6,558 votes in the declaration of the election result in Putney.
The first published result had shown Labour’s Fleur Anderson held onto the seat with 20,952 votes, beating Conservative Lee Roberts who received 10,011.
However, almost two weeks after the 4 July general election, the council revealed it had made a mistake and published a revised list of the results on its website.
The revision did not impact the overall result, or ranking, but provided Ms Anderson with a greater majority. She took 24,113 votes, increasing her share of the vote to almost 49 per cent.
Mr Roberts received 11,625 votes. He was followed by Kieren Michael McCarthy, the Lib Dem candidate, with 5,932 and Fergal McEntee, of the Green Party, with 3,721.
In a statement, Wandsworth Council said: “We acknowledge a spreadsheet issue that resulted in not all the properly counted and allocated votes being included in the announcement on the night in the Putney election count for the general election 2024.
“This was identified and the figures on this page have been updated. This did not affect the result or the order of the candidates.
“While we are confident this was an isolated incident we are taking this opportunity to review processes with a particular focus on spreadsheet procedures.”
However, some expressed anger at the mistake.
Aled Richards-Jones, the leader of the Conservative group on the council, said: “Wandsworth residents deserve urgent clarification about how an error of this magnitude could have occurred, why it wasn’t detected at the time and the steps the council is taking to ensure this can never happen again.”
Former education minister Justine Greening had held the Putney seat for the Tory party from 2005, until in 2019 she rebelled against Boris Johnson’s government and became an independent MP.
The seat was then won by Ms Anderson for Labour with a majority of more than 4,700 in 2019.