A would-be Tory MP has been reported to the election watchdog amid Labour fears of “potential interference” in the postal voting process.

Workington Conservative hopeful – and Allerdale Council deputy leader – Mark Jenkinson has strongly denied that he has broken any rules.

His party has described the complaint as evidence of “sour grapes” from Labour, in a seat seen by pundits as a key election battleground.

Labour’s External Governance department has called on the Electoral Commission to investigate the allegations, but Conservatives say they are “confident” everything had been done in line with the rules.

A spokesman for the Commission – the independent regulator dealing with electoral standards – has confirmed it is aware of the complaint and have contacted those involved.

Labour says Mr Jenkinson sent postal vote application forms to residents, along with a letter asking them to complete the paperwork and return them to his office at the Conservative Club in Workington.

They have cited section 1.3 of the Electoral Commission’s ‘Code of Conduct for Campaigners’ which states campaigners should ensure that the local Electoral Registration Officer’s address is “clearly provided” as the preferred address for the return of registration and absent vote application forms.

The rules add that following these procedures would “minimise the risk of suspicion that completed applications could be altered or inadvertently lost or destroyed.”

A Labour Party spokesman said: “This appears to be a clear breach of the code of conduct.

“The Conservative candidate’s letter does not give the Electoral Registration Officer as the preferred return address for absent voting applications, and in fact encourages electors to return their forms to the Conservative campaign office.

“It’s vital that all election candidates follow the code of conduct to avoid any hint of suspicion that they may be interfering with the democratic process.

“I would urge anyone who has applied for a postal vote to check as soon as possible with the elections department at Allerdale Council that they have received the application.”

But the Conservatives have claimed that Mr Jenkinson’s letter was sent before the regulated period and purdah.

A copy of the application form sent with the letter shows the Allerdale Council address, giving options of where to return the form.

A spokesman for the Conservatives, speaking on behalf of Mr Jenkinson, said: “This is just sour grapes by Labour who know their policies aren’t working for Workington.

“We are content that everything we have done is in line with the Electoral Commission’s Guidance and was prior to purdah and the regulated period.

“We support democracy and with a winter election want everyone to have a chance to vote – even if they can’t get out because of the dark nights and bad weather.”

The Electoral Commission was unable to put a timescale on their investigation, with every complaint dealt with on a “case by case basis”.

Separately, Labour has also written to Allerdale Council asking whether the outspoken Conservative was given permission to use what they claim is “council resources” to promote his campaign.

The original letter from Mr Jenkinson shows a photograph of the councillor in front of the council logo, which Labour says is “under copyright”.

A Labour spokesman said: “If the council did not agree to the use of the copyrights then it should report the matter to the police as a breach of copyright as defined by the Fraud Act 2006 and pursue a breach of copyright claim in the civil court.

“Failure by the council to assert a breach of copyright claim will be seen by us as implicit permission by the council for the use of the copyright and, therefore, a breach of the law by the council itself.

“Alternatively, if the council decides to give retrospective permission to the Conservative candidate for use of the copyright, we would expect the council to charge Mr Jenkinson and/or his agent an amount to the value of the mailing or the just and equitable figure of £1,000, whichever is the greater.Failure to do this will mean public resources have been provided by the council to promote a candidate.”

Allerdale Council has been approached for comment.