A charity is taking Watford Borough Council to a local authority watchdog over a dispute which erupted over a £500,000 repair bill.

Age UK Hertfordshire said it was going ask the Local Government Ombudsman to investigate how the council’s property department came to charge it the potentially-bankrupting sum.

The move comes after Watford’s Liberal Democrat administration has rejected calls for the council to launch an internal investigation into the matter.

Karen Whitaker, chairman of trustees at Age UK Hertfordshire, said she wanted to know if any other charities had experienced the same troubles hers had had with the council.

Watford mayor Dorothy Thornton was unfazed by the move and said the borough was ready to put its case to the ombudsman.

The development comes as the latest twist in the acrimonious saga between the charity and the council, which started after Age UK left the Watford-owned Harebreaks building last year.

The council said the building needed £500,000 worth of repairs, which the charity would have to pay for. When Age UK refused, the council threatened legal action.

The dispute has since been resolved and the charity is still a tenant of the council in a building in Exchange Road. Mrs Whitaker said the charity would not be happy until there was an investigation into the original bill.

She said: “We want to know if it is carelessness, which it is bad, or it is indicative of the management.”

Mayor Thornhill said she thought the real victims in episode between Watford and Age UK were the borough’s taxpayers.

She said the council was looking to lease out the Harebreaks building again and the repairs were being paid for out of public funds.

“That is the loser in all this, the taxpayer,” added Mayor Thornhill. “The money we need to find (for the Harebreaks) has to come from somewhere else.”