The National Bullying Helpline has closed due to lack of funding and the resignation of its founder and chief executive, Christine Pratt.

A spokesman for the charity said an increased workload and trying to secure funding for the charity had taken its toll on Pratt’s health:

“This last year, calls to our helpline have trebled and we have had to take on additional volunteers and resources to meet demand,” he said. “Undoubtedly, the closure of our charity will be a great loss to the public.”

The National Bullying Helpline (NBH) was embroiled in a political row last year after Pratt claimed that the charity had received calls from No.10 staff following accusations in the press that Gordon Brown had bullied civil servants.

In a video on the BBC news website, Pratt said she was not suggesting that Gordon Brown was a bully, but claimed staff in his office with issues and concerns had contacted the National Bullying Helpline.

In another BBC video, Pratt denied claims that her actions were politically motivated.

Pratt’s actions led to the resignation of all of NBH's charity patrons, including Tory MP Ann Widdecome who complained that Pratt has breached caller confidentiality.

The charity is still being investigated by the Charity Commission who opened a statutory inquiry into NBH last year in the wake of 160 complaints it received following the Gordon Brown bullying row.

In a statement the Commission said concerns had been raised about the protection of confidential information held by the charity as a result of the operation of the charity's helpline for victims of bullying.

The Helplines Association said in a statement that the Charity Commission’s forthcoming statement on its investigation into the charity would “finally draw a line under the controversy”.