A Labour politician is under investigation after a complaint to the Parliamentary Commissioner for Standards.

The party's Tottenham candidate David Lammy, who has held the seat for 15 years, is being investigated over allegations a letter he signed broke parliamentary rules on correspondence.

The letter to deputy Prime Minister Nick Clegg, co-signed by the Labour candidate for Hornsey & Wood Green Catherine West, requested an urgent meeting to discuss redevelopment on the site of St Ann’s Hospital in St Ann’s Road, Tottenham.

MPs are forbidden from using official correspondence to campaign in a General Election and should Mr Lammy be re-elected the commissioner will look into the issue.

The commissioner’s office confirmed a complaint was made but said that it would not reveal the identity of the complainant until the matter is closed.

The Liberal Democrats said they do not know who made the complaint and that it would be a violation of Parliamentary standards for anyone to reveal that information.

A spokesman for David Lammy said: "Mental Health services are a very important matter for people who live in Haringey.

“The letter was sent to the deputy Prime Minister requesting an urgent meeting to discuss issues facing St Ann’s Hospital and was not sent in a campaigning capacity.”