Conservative politician Craig Mackinlay has been cleared of falsifying election expenses.
The MP for South Thanet had denied making false declarations during his 2015 campaign, when he beat then-UKIP leader Nigel Farage to the seat.
Mr Mackinlay, 52, had been accused of failing to declare more than £60,000 spent on staffing, hotels and adverts.
Party activist Marion Little, 63, was given a suspended sentence after being found guilty of two charges.
Little, who had effectively run the 2015 election campaign, was found guilty of two counts of encouraging or assisting an offence, but cleared of a third.
The long-time Tory party member, from Ware, Hertfordshire, had “acted dishonestly by preparing returns she knew were not completed nor accurate,” Judge Mr Justice Edis said.
He described Little’s actions as a “sustained and deliberate course of conduct”.
Handing her a nine-month sentence, suspended for two years, the judge said Little had been “carried away by her conviction” that defeating Mr Farage was an “overwhelmingly important political objective”.
He said the only reason she was not being given a custodial sentence was because she was caring for her husband, who is terminally ill.
Jurors at Southwark Crown Court had deliberated for more than 53 hours before reaching their verdicts.
Mr Mackinlay responded on Twitter, simply writing #notguilty.
Prosecutor Michelle Nelson told jurors South Thanet would usually have been seen as a safe seat, but Mr Farage’s run as UKIP candidate had been regarded as the chance to “knock him out” of politics.
Mr Mackinlay told the court the Conservative Party HQ had “recognised the fear of Farage” and offered to pay for a campaign manager.
He said the South Thanet seat would be “looked at and pored over very carefully” and said he was told during the 2015 campaign that spending was “perilously close” to the limit.
The prosecution’s case centred around claims some costs for activists and party workers were recorded as national rather than local election expenses, to ensure spending limits weren’t breached.
‘No election rules’
Declared spending came in under the £52,000 constituency limit, but prosecutors claimed more than £60,000 went undeclared.
Mr Mackinlay eventually won the seat, in what the court previously heard was a “nasty” election.
The MP’s agent, Nathan Gray, was acquitted on 13 December.
Mr Gray, 29, of Hawkhurst in Kent had faced one count of making a false election expenses declaration.