“There is a whole world beyond Liverpool Street,” says a London Assembly member trying to persuade Sadiq Khan to rename the Hammersmith & City line the Hammersmith & Barking line.

Andrew Boff, a Conservative assembly member who lives in Barking, put his demand to Mr Khan at last week’s mayoral question time - although he has only just responded.

In his question, he said: “Will you either a) rename the Hammersmith & City Line the Hammersmith & Barking Line or b) Support Barking becoming a city?”

He adds: “The future of London can be found in the east and the transport system should recognise that.

“A name change for the Hammersmith & City line would give Barking the recognition that it deserves and prove the mayor is backing the renaissance in the east.

“I’ve given him two choices, one he can control, one he can’t.”

Mr Khan said: “The Hammersmith & City line is appropriate for the areas that it serves and I see no benefit and only extensive cost in time and finances to rebrand the line.

“Transport for London would have to update every map and direction sign, as well as all announcements on every affected train and station on the network.”