Mayor of Tower Hamlets Lutfur Rahman has been accused of “siphoning off cash to pay for propaganda” after the taxpayer footed a £20,000 bill for political advertisements promoting him.

Broadcasting watchdog Ofcom ruled in January that adverts shown the previous year breached its code and amounted to a party political broadcast for the mayor.

An investigation has now revealed the £20,000 cost to the taxpayer for the adverts, which were broadcast on five Bengali television channels in January 2012.

Public spending pressure group the Taxpayers’ Alliance has now called on Mayor Rahman to repay the money himself.

Campaign manager Robert Oxley said: “Using taxpayers’ money to fund the mayor’s political campaigning is a disgusting abuse of taxpayers’ resources.

“It speaks volumes that an administration meant to be finding ways to save residents’ money is instead siphoning off cash to pay for their own propaganda.”

Labour opposition councillors called for an investigation following Ofcom’s ruling, which came after a complaint from Conservative group leader Cllr Peter Golds.

Outgoing Labour group leader Cllr Joshua Peck said: “Spending £20,000 of the public’s money on self-serving publicity is scandalous.

“When the mayor is cutting frontline services and social workers in the borough, spending £20,000 on adverts which could instead have been used to protect residents is utterly outrageous.”

Mayor Rahman has been widely criticised since Ofcom published its ruling, with local government minister Brandon Lewis accusing his administration of a “worrying pattern of divisive community politics and mismanagement of council staff and resources”.

The adverts featured photographs of Mayor Rahman in the cab of a digger and inspecting a flat, and outlined his aims for improving the borough’s housing situation.

Despite repeated requests, the council failed to provide a comment.