Sir Keir Starmer’s party have sent a cease-and-desist letter demanding Lib Dem leaflets are destroyed – accusing their political rivals of going “feral” and making things up about Labour candidate Alistair Strathern.
But the Lib Dems have fired back – accusing Labour of “cheap stunts” and “dirty tricks” while refusing to ditch the controversial leaflets.
Both parties are hoping to overturn a 24,000 majority in the 19 October contest arranged after Boris Johnson ally Nadine Dorries finally quit parliament earlier month.
But Labour are furious about attempts to undermine Mr Strathern, after the campaign literature for Lib Dem candidate Emma-Holland-Lindsay suggested her Labour rival was an outsider.
The letter – which alleges two breaches of the Representation of the People Act – says the Lib Dems have made “false statements” about Mr Strathern by claiming that he does not live in the constituency and is a London councillor.
But a Lib Dem source said Mr Strathern, who grew up in Mid Bedfordshire, only moved back to the constituency after got selected as the Labour candidate.
The Labour letter also accused Sir Ed’s party of “misleading” voters in the area with a dodgy bar chart based on recent polling.
It condemned “a misleading bar chart which shows a 7 per cent increase in voters polled favouring the Liberal Democrats against a 5 per cent increase for the Conservatives, thereby giving the impression that the Liberal Democrats are in first place in a neck-to-neck contest with the Conservatives”.
It said this was “incorrect” because recent polling has the Liberal Democrats in third place, behind both Labour and the Tories. Sir Keir’s party claimed tactics “amounts to the corrupt practice of undue influence”.
Peter Kyle MP, Labour’s campaign lead in Mid Bedfordshire said: “The Lib Dem campaign has gone feral”, before added: “The Lib Dems do nothing but fill people’s letterboxes with lies, smears and innuendo.”
But the Lib Dems are refusing to withdraw the leaflets and accused Labour of a “desperate” tactics.
Helen Morgan, MP for North Shropshire, said: “People in Mid Bedfordshire will be livid over Labour threats to waste police time, when locally people can’t remember the last time they saw a bobby on the beat.”
The Lib Dem MP added: “This is dirty tricks from a desperate Labour campaign that knows it cannot win Mid Bedfordshire.”
She added: “If Labour were serious about this by-election, they would not have picked a candidate who lived 50 miles away when selected, and until just a few days ago was an elected councillor in east London.”
The latest poll showed Labour and the Tories neck and neck in the byelection battle for Ms Dorries old seat, with both on 29 per cent and the Lib Dems on 22 per cent.
The Survation survey offers evidence that a split in the “progressive” vote could allow Rishi Sunak’s party to hold onto the seat despite wider unpopularity.
Anti-Tory tactical voting campaigners has pushed Labour and the Lib Dems to form an unofficial electoral pact so only one of the big parties pushes to take the blue wall stronghold.
Despite trailing in the latest poll, Lib Dem officials have argued that there is a natural ceiling to the Labour vote in Mid Bedfordshire because of the demographics in the rural constituency. “It will be won and lost in the villages,” said a party source.