Labour MP Heidi Alexander resigns to become London deputy mayor

The move will trigger a by-election in Lewisham East, a Labour stronghold with an active Momentum presence

Heidi Alexander will step down as MP for Lewisham East in the summer (Getty)

Labour MP Heidi Alexander will stand down from parliament, triggering what could be a fiercely contested by-election in her southeast London seat.

Ms Alexander, who resigned from Jeremy Corbyn’s shadow cabinet in 2016, will head to the capital’s City Hall to become London’s deputy mayor for transport, in the latest in a string of moderate MPs seeking opportunities outside the parliamentary party.

Her departure from the Commons in the summer will trigger a by-election in Lewisham East, where pro-Corbyn group Momentum has an active presence.

She will replace current deputy mayor Val Shawcross, who is stepping down after 18 years at the Greater London Authority.

It is not possible for Ms Alexander to be both an MP and a deputy mayor, City Hall said.

Left-wing Labour sources pointed to local councillor Sakina Sheikh, who promptly announced her ambitions to stand, as a potential candidate for the left slate.

The contest will shine a light on divisions in the party as different Labour factions are expected battle it out to get onto the ballot paper.

While the borough recently elected Labour centre-left candidate Damien Egan as mayor over Momentum’s candidate Paul Bell, the powerful group of Mr Corbyn’s supporters has a big presence in the area.

Announcing her move, Ms Alexander said: “I am really excited to be joining Sadiq and the team at City Hall. Val is going to be a hard act to follow but I can’t wait to get started.

“After eight years as the Member of Parliament for Lewisham East and six years as a local councillor, I know just how important it is we ensure everyone has access to a high-quality and affordable public transport network, with safe cycling routes across the capital. London is a fantastic city.

“I know Sadiq wants its transport system to be the envy of the world and I am looking forward to playing my part in making that happen.”

Since quitting the shadow cabinet, Ms Alexander has campaigned for Britain to remain in the single market, chairing the party’s backbench campaign on the issue.

She has been an outspoken critic of the Labour leadership, which she described as “dysfunctional” and “so inept, so unprofessional, so shoddy”.

Sadiq Khan, London mayor, said: “Heidi knows this city inside out, and her work both as shadow health secretary and campaigning over the best Brexit deal has demonstrated the terrific job she will do as part of my team standing up for London.

“Heidi is respected across the political divide as a parliamentarian and campaigner and Londoners can be confident she will ensure we deliver our ambitious plans to transform London’s transport network over the coming years.”

He paid tribute to outgoing deputy mayor Ms Shawcross for her “exceptional service” and “deep expertise” during her tenure.

Ms Alexander was previously a deputy mayor of Lewisham and a member of London Councils’ Transport and Environment Committee, before being elected to parliament in 2010.

She also hit the headlines last year for asking Theresa May whether she would extend dangerous driving laws to cover cycling, after her constituent Kim Briggs was killed by a rider who didn’t have a front brake on his bicycle.

Labour MP Dan Jarvis was elected as mayor for Sheffield City Region last week, although he remains MP for Barnsley, while former leadership contender Andy Burnham stood down to become mayor of Greater Manchester.

Tristram Hunt triggered a by-election in Stoke-on-Trent Central when he resigned to become director of the V&A museum.