A claim that a Cumbrian candidate has breached election rules over mail sent to constituents is poised to be considered by a parliamentary standards watchdog.

The Conservatives claim Labour’s Sue Hayman, who is seeking re-election in Workington, has made “improper use” of House of Commons resources by sending out unsolicited mail on official stationery.

Mrs Hayman denies the claim, saying she has not breached any rules or sent out any communications on House of Commons stationery since Parliament was dissolved last month.

A complaint sent to the Serjeant of Arms at the House of Commons in London is set to be forwarded on to the Commissioner for Standards.

The commissioner is not able to look into the issue until after the election.

James Devenish, Conservative election agent in the Workington constituency, wrote the formal letter of complaint to the Serjeant of Arms.

In it he includes a photograph of a heap of mail, showing a letter with the official House of Commons stamp.

Mr Devenish said the photograph, which has been shared on Twitter, “clearly shows a postcard sized House of Commons envelope within a small build up of mail within an empty house in the Cockermouth area of the constituency”.

His letter adds: “The envelope, which can only have been received in the past few weeks, is not addressed to an individual, but to the property, which would suggest it is an unsolicited communication, rather than being connected to any ongoing correspondence.”

He says that using official stationery in an election period could “gain unfair advantage” and calls for an investigation.

However Mrs Hayman was quick to set the record straight.

She said that they have looked into the matter after seeing the photograph, and said it was among a series of letters sent out to flood-hit properties prior to parliament being dissolved.

She believes the photograph was taken through the glass door of an empty property and questioned whether this should have happened, and whether it should have been shared publicly.

Regardless, she said she believes the letter was among a batch sent out on April 28 asking residents for feedback about the ‘flood re’ insurance scheme for flooded properties.

“After the floods we sent out information to everyone affected. Before we knew the election was coming, we had drawn up a survey to ask about that, for feedback,” she said.

“It was ready to go out when the election was called. I contacted Parliament and asked if we were still able to send it out.”

She stressed they were addressed to the properties that had been flooded, rather than householders, and were in no way unsolicited election material.

Mrs Hayman added that any correspondence sent out since Parliament was dissolved has been on plain stationery, with no reference to the House of Commons.

Mr Devenish has also sent his letter of complaint to the Returning Officer in the Workington constituency.

Mrs Hayman was joined on the campaign trail by former Workington MP Dale Campbell-Savours in the town centre at the weekend.

She said she has been working closely with Baron Campbell-Savours, who now sits in the House of Lords, since she was elected to Parliament in 2015.

She said: “He’s been incredibly supportive and was very keen to show his support for my campaign.

“It was lovely to have him join us. I really appreciate all his support.”