A complaint that the leader of the giant Unite union breached rules when he was re-elected last year has been rejected.
Len McCluskey beat Gerard Coyne last April, but the defeated candidate claimed there should not have been an election for general secretary because the term of office had not expired.
Mr Coyne asked Jeffrey Burke QC, acting on behalf of the Certification Officer, to order a rerun of the contest but the complaint has been rejected.
Another hearing will be held next month to consider a series of other complaints from Mr Coyne over the running of the election.
The Certification Officer deals with complaints about union elections and other union issues.
A Unite spokesman said: "Unite welcomes the assistant certification officer's rejection of Mr Coyne's complaint and his ruling that the union acted in accordance with its rules in calling a general secretary election.
"It should be noted that when the general secretary election was called no complaints or objections were made by Mr Coyne or any other individuals.
"Unite presumes that Mr Coyne will accept the judgment and looks forward to the election being fully upheld following June's hearing, allowing the union to focus unhindered on the job of representing its members."
Mr Coyne said: "I am naturally disappointed by today's ruling.
"I believe that Len McCluskey was wrong to pick and choose the timing of his re-election campaign, even though the Certification Officer has now found in his favour.
"This was one of nine complaints about the conduct of this election that I have lodged with the Certification Officer.
"It was heard separately because, as the Certification Officer rightly pointed out, if his ruling had been different on this point, there would have been no need to consider the other eight.
"Those other complaints will be dealt with at a week-long hearing in June.
"I am confident that the evidence we will present will demonstrate that this election was not conducted properly or in a way that respected the interests of Unite's members.
"I will now be considering whether to appeal this decision to the Employment Appeal Tribunal.
"Unfortunately we do not have the deep pockets that Unite has, which would have enabled them to fund an appeal without difficulty if the decision had gone the other way."