In a dig at the Labour compliance unit, which some party members claim has been unfairly denying leadership ballots to potential voters, Farron said the LibDems would not target anyone “for thinking the wrong thoughts or belonging to the wrong group”.
“But you will get purged for wimping out and knocking off at 9.30 on polling day,” he told the party conference’s members rally in Brighton.
Farron said the LibDems victory in the Mosborough byelection in Sheffield, where the party came from fourth place to win the council seat, was because local Labour activists were preoccupied with the party’s leadership election.
“Just yards away from where the LibDem team were knocking on doors, some of the local Momentum activists were in the pub. They were telephone canvassing for Corbyn in the Labour leadership election.
“Meanwhile in the real world outside that rather nice Sheffield pub, real people were voting in a real election.”
A Momentum spokesperson said: “Sheffield Momentum members and supporters campaigned for a Labour victory during the Mosborough by-election, alongside phone-banking in the leadership election just like Owen Smith supporters. We are looking forward to this leadership contest ending so we can focus entirely on building Labour victories.”
Farron said the donation of £2.1mn to the party by Labour peer Lord Sainsbury before the EU referendum showed his party, rather than Labour, was seen the “movement capable of delivering a pro-European campaign” – a pitch to other Labour donors who have expressed some hesitation at supporting the party under Corbyn’s leadership.
“In a few days time, Labour looks like choosing to continue its flight into fantasy and pointlessness,” Farron said of the Labour leadership election, where Corbyn is expected to defeat his rival Smith.
Farron, whose own party is currently polling at about 8% nationwide, said the LibDems were not prepared to accept the result of the EU referendum and said the defeat of the Remain campaign was “temporary”.
“I will not be told that I am not a European. I will not accept that my country has been lost to the nationalists,” he said. “Britain can still stand tall in Europe and Britain can still be freed from the Tories. Let’s take back control.”
Earlier, Farron told Labour and Tory moderates they could find a new political home by defecting to his party.