Peter Mandelson is due to take a job in Brussels

Mr Mallon, now the independent mayor of Middlesbrough, said he did not want to give up his current job.

The Labour Party was reported to be considering Mr Mallon, nicknamed "Robocop" for his zero-tolerance approach to crime, as a candidate.

Last week Mr Mandelson accepted a job as a European commissioner.

A spokesman for Middlesbrough Council said: "The mayor has made it clear that he will not be seeking any nominations in the forthcoming by-election in Hartlepool because of his on-going commitments as Mayor of Middlesbrough."

Ray Mallon wants to remain mayor of Middlesbrough

Mr Mandelson approached Mr Mallon over the weekend to ask him to stand, according to London's Evening Standard.

A spokesperson for the Labour party said it was their policy not to comment during the candidate selection process.

Hartlepool has been a Labour constituency for 40 years, but many in the Labour Party fear the Liberal Democrats could overturn Mr Mandelson's 14,571 majority.

The Lib Dems were due to announce their candidate for the Hartlepool by-election on Thursday evening.

Labour and the Conservatives both say they are in the process of selecting their candidates.

Former television presenter and Euro MP Robert Kilroy-Silk has said he is "seriously considering" standing as a candidate for the UK Independence Party.