The Labour Party has retained the south London constituency of Tooting in a bypoll triggered by the election of Sadiq Khan as the mayor of London in May.
Pakistan-origin Rosena Allin-Khan, a junior doctor in the National Health Service, won the seat, defeating Conservative Dan Watkins, who was also placed second in the May 2015 elections when Khan had won the seat.
There were no celebrations after the result was declared on Thursday night in view of the killing earlier in the day of Jo Cox, the Labour MP from west Yorkshire. Allin-Khan paid tribute to the "proud and passionate" Cox.
She said: "Jo's death reminds us that our democracy is precious but fragile - we must never forget to cherish it. Thousands of people voted today and we are all here in recognition of our democratic values."
Clive Efford, the Labour MP for Eltham, said there would be no celebrations in Tooting. “It's not appropriate. No-one feels in the mood. This has never happened on an election campaign. We just had to dry our tears and get out there," he said.
Cox, a popular first-time Labour MP from West Yorkshire, died on Thursday after being stabbed and shot by a man in her constituency.