A councillor is to step down after his appointment to City Hall.

Stoke Newington councillor Mete Coban, who became Hackney’s youngest ever councillor in 2014, has been appointed Deputy Mayor of London for Environment and Energy by Sadiq Khan.

His departure has triggered the seventh by-election in Hackney so far this year.

Mr Coban said the decision to stand down was a “bittersweet moment”, but that his new role is an “incredible opportunity”.

“It has been a really difficult decision to make, as Hackney is not just my home; it’s my story and who I am,” he added.

“Serving as a councillor in the place I call home has been the greatest honour and privilege of my life, and I couldn’t be more proud of my contribution to creating a greener, healthier Hackney over the past decade.”

He is due to start in his new role tomorrow (July 25).

As a councillor and cabinet member for climate change, environment and transport, Mr Coban helped to expand the Hackney’s low traffic neighbourhoods, roll out 3,000 EV chargers and launch the Community Energy Fund.

During this time, he faced criticism for the number of flights he takes.

The Telegraph calculated that he had racked up approximately 40,000 air miles while warning people that “the way we travel” can “have a huge impact on the climate”.

Mr Coban defended his flights, saying they were for the purpose of his non-partisan campaign group My Life My Say, which seeks to increase youth voter turnout.

He has also now stepped down from his role as chief executive of My Life My Say.

Hackney Mayor Caroline Woodley said Mr Coban “has been such an energetic and exciting colleague to work with”.

She added: “He has been instrumental in making it easier and safer for people to move safely about Hackney, one of the busiest boroughs in London, and has been the driving force behind our vital investment in renewable community energy”.

She continued: “While we will be sad to see him go, this is an absolutely amazing opportunity, and it can only be good news for our borough to have such a dedicated climate champion at the heart of City Hall.”