The Watford Labour parliamentary candidate selection process has had to be extended after complaints were made about "postal vote irregularities".

It has led to a hustings meeting, an opportunity for candidates to address voters, which was scheduled to take place tonight, to be cancelled.

Last week, it was reported that a row had broken out after the Labour's governing National Executive Committee (NEC) overruled the decision by the local party not to shortlist  Mike Hedges as a candidate.

Now the saga has escalated after Unite the union made a formal complaint to the Labour Party.

Unite, who are backing Mr Hedges, say that emergency postal voting forms handed out to members in early November were wrong, with no space for a signature.

Postal voting requires a signature otherwise a vote cannot be counted. It remains separate from a ballot paper to ensure secrecy of a person's vote.

In the letter from Unite to the Labour Party, it said “members received phone calls for emergency postal vote requests, as they had filled in the wrong form. They were then visited by people saying they were from the Labour Party who brought with them a new emergency post form which they signed. t

"They then gave them a ballot paper which the member filled in and the person who came round took the ballot paper back with them”.

A spokesperson for Unite the Union said: "We have not once had case for complaint. The situation in Watford is highly irregular: a candidate's supporter should not be walking around with blank ballot papers."

Unite also claim that postal votes were not being kept in a secure location.

The union believe the Labour Party Office on St Albans Road, which was listed as the return address for postal voters, does not represent a “secure office” because a candidate has access to the office.

Chris4Watford, the campaign team behind fellow Watford Labour candidate Chris Ostrowski, are "dismayed" at the decision by the national Labour Party to delay the parliamentary process.

"This comes on the back of a decision by the Chair of the NEC Organisation Committee, himself a UNITE official, to impose the UNITE sponsored candidate onto the Watford short list.

"With regards to the first complaint is concerned, there was a fault in an early edition of the Emergency Postal Vote form as it did not ask for a signature. This was quickly rectified but a few members sent the first form in without signature. The Procedures Secretary gave them the opportunity to sign the form before issuing them with a postal vote pack. There is nothing irregular about that in our view.

"The second complaint is wholly unsubstantiated as all postal votes are delivered to a secure locked post box to which only the Procedures Secretary has a key.

"The office in which the Procedures Secretary works has been locked by him during this process; only he has the key. No office PCs have been used - all work was undertaken on his personal lap top.”

The row erupted earlier this month after the Watford Labour Party were ordered to place Mr Hedges on the shortlist of candidates.

The Islington resident, a taxi driver who once chauffeured round Jeremy Corbyn during the Labour leader's first election campaign, had not been selected after interview, despite receiving a large backing and a number of nominations.

As a result of the order, Mr Hedges was shortlisted alongside Sucharita Seth, Jocelynne Scutt, and Chris Ostrowski, who was the party's candidate at the last election.

A Labour spokesperson said: "The Labour Party is proud that local party members can participate in the democratic selection of their own local candidates.

“We are satisfied that selections are taking place in line with Labour's rules and procedures."