Jack Dromey, the candidate favoured by Tony Blair, has written to the Government's union watchdog alleging that the present leader of the Transport and General Workers' Union has misused the organisation's resources to fund his campaign.
The allegation by Mr Dromey seems to indicate a degree of pessimism about the outcome of the election, given that the victor is unlikely to question the result. It is thought however that the challenger is only likely to take the matter further if he loses by a narrow margin.
The union yesterday received a letter from the official Certificiation Officer calling for clarification of the union's rules on the use of union funds in election campaigns.
Mr Dromey's complaints to the officer follow similar protests from lay members. Accusations from a principal in the election however, especially one who has received the private backing of the Labour leadership, make the situation far more serious.
It is understood that the complaints do not allege breaches of criminal or civil law, but accuse Bill Morris, the leader, of ignoring the union's rule book. The Certification Officer does not have the power to order a fresh poll, but could produce a report which would prompt a decision by the union executive to rerun the election.