Bow and Bromley by-election, 1912

The Bow and Bromley by-election was a by-election held on 26 November 1912 for the British House of Commons constituency of Bow and Bromley. It was triggered when the Labour Party Member of Parliament (MP), George Lansbury, accepted the post of Steward of the Chiltern Hundreds as a technical measure enabling him to leave Parliament.

Bow and Bromley was a marginal constituency. It had been held by the Liberal Party from 1906 until 1910 and by the Conservative Party from 1895 until 1906 and during 1910. At the general election of December 1910, Lansbury had gained the seat for Labour with a majority of 11.1%.

Lansbury had become a strong supporter of women's suffrage. Unusually among male politicians of the time, he supported the actions of militant suffragettes such as the Women's Social and Political Union (WSPU). While support for women's suffrage was official Labour policy, Lansbury felt that this support was lukewarm, and so in October 1912 he travelled to Boulogne-sur-Mer with Emmeline Pankhurst, where he met WSPU leader Christabel Pankhurst.

Lansbury decided to resign his seat and contest the resulting by-election on a platform of "Votes for Women". He was unable to gain official Labour Party support, and instead ran as the "Women's Suffrage and Socialist" candidate. He was supported by his Constituency Labour Party (CLP), including J. H. Banks and Edgar Lansbury, by some prominent Labour figures including Keir Hardie and Philip Snowden, by Liberal Party MP Josiah Wedgwood and by journalist H. N. Brailsford. Millicent Fawcett, leader of the WSPU's rival the National Union of Women's Suffrage Societies also campaigned for Lansbury.