A former Labour MP and husband of a city councillor has been appointed to represent prosecutors in the Birmingham election court case.

Gerry Bermingham QC is representing the interests of the Director of Public Prosecutions at the court which is considering claims that Labour councillor Muhammed Afzal won his seat in Aston after organising a smear campaign against Liberal Democrat opponent Saeed Aehmed.

Mr Bermingham was appointed to advise on whether allegations of "illegal practices" levelled against Coun Afzal, one of Labour's leading figures in Birmingham, should be investigated by the police.

His appointment came after Elections Commissioner Timothy Straker QC, presiding over the trial, expressed concern that witnesses ought to be cross-examined by counsel for the DPP with a view to the possibility of a criminal investigation being launched.

A former MP for St Helen's, Mr Bermingham is married to Jilly, a Labour member of Birmingham City Council who represents Erdington. Mr Bermingham's role was questioned yesterday by Graham Brodie, representing Mr Aehmed. Mr Brodie said he was not suggesting Mr Bermingham was anything other than independent, but he was concerned about the appearance his appointment might have to people outside of the court.

His comments were accompanied by an attack on the DPP, which Mr Brodie said had responded in a "grossly inadequate" way to an order by Mr Straker to trace witnesses who claimed to be too scared to come to court. Mr Brodie said: "The Director of Public Prosecutions should be seen as wholly independent from the parties.

"The problem here is not that Mr Bermingham isn't independent of the parties. I don't suggest that for one moment. It is the appearance. Mr Bermingham has a long-standing affiliation to the Labour Party and his wife is a local councillor."

Mr Bermingham told the court he was saddened at the comment which he took as a "personal slur".

He added: "I am a member of the Bar and utterly independent."

All of the allegations against Coun Afzal – that he sought to improperly influence voters by stating wrongly that Mr Aehmed had been arrested for postal vote fraud and was guilty of fraudulently obtaining disability grants – are denied.

Three of the five missing witnesses have been traced and are now willing to come to court. One, Iqbal Khan, who appeared yesterday, told the court he had signed a witness statement which had been written for him while sitting in Saeed Aehmed's car in the dark. He could not see the statement or read it since he does not speak English.

After having the statement translated, he disagreed with everything in it other than confirmation of his membership of the Liberal Democrat Party. Mr Khan told the court his "conscience had been pinched" and he realised it would be wrong to give evidence on behalf of Mr Aehmed.

Mr Khan, of Weston Terrace, Handsworth, originally declined to come to court after producing a doctor's note declaring he was suffering from dizziness, hypertension, bowel disorder and general debility. Yesterday, he admitted that shortly after obtaining the sick note he took a business trip which involved flying from the UK to Istanbul, Istanbul to Dubai, Dubai to Istanbul, Istanbul to the Ukraine and the Ukraine to the UK.

"Anyone can suffer a stomach disorder," he told the court.

Efforts to find two other witnesses have not proved successful. The court was told police have not yet attempted to find the missing two, although their addresses were passed to the DPP earlier this week.

Mr Brodie said: "The role the DPP seems to want to adopt in these proceedings is from our point of view grossly inadequate."

He said that in the context of witnesses sending emails to court asking for 24-hour protection, the DPP's reaction amounted to "lackadaisical" behaviour.

Mr Brodie was also critical of the DPP's reluctance to order its counsel to attend every session of the court.

The procedure, whereby transcripts of the proceedings would be sent to DPP headquarters in York and Mr Bermingham would only be ordered to attend if a matter of interest cropped up, was inadequate and would preclude witnesses from being cross-examined, Mr Brodie argued.

The case continues.