Labour has put together a shortlist dominated by junior doctors as they fight to retain Sadiq Khan’s marginal seat of Tooting. In addition, they have tapped Naushabah Khan, the party’s candidate in the Rochester and Strood by-election, in what is expected to be a tough fight. The Conservative candidate, Dan Watkins, has been in place since the general election, where he was narrowly defeated by Sadiq Khan.

Two of the shortlist are doctors: Rosena Allin-Khan, also deputy leader of the Labour group on Wandsworth Council, Mike McLoughlin, a junior doctor at St Thomas Hospital and local resident. Allin-Khan is widely-regarded as the candidate to beat, and has been heavily tipped by the bookmakers. She will face heavyweight opposition from the trade union movement in the shape of Martin Smith, national organiser for the GMB.

Naushabah Khan, who came to Labour through the anti-fascist grouping Hope not Hate, is considered, both inside and outside the Labour party, to have made a good account of herself in a tricky by-election for Labour, in which they were squeezed between the Conservatives and Ukip. Jasvir Singh, a barrister, and local resident, rounds out the shortlist.

McLoughlin, meanwhile, is a Tooting resident who came to London from Northern Ireland to practice medicine. If selected and elected he would take the number of openly LGBT MPs at Westminster to 35. Party insiders believe that the presence of a medical professional on the ballot will help Labour in a seat that is rapidly gentrifying, while having a candidate from a visible minority will also aid the party's turnout efforts. Labour hope they can use the memory of the Goldsmith campaign to bolster turnout in the by-election, which is expected to be close.