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.
Jurors at Southwark Crown Court deliberated for more than 53 hours before reaching a verdict.
Party activist Marion Little, 63, from Ware, Hertfordshire, who was tried alongside Mr Mackinlay, was found guilty of two counts of encouraging or assisting an offence.
She was cleared on a further count of the same charge.
Mr Mackinlay responded to the verdict on Twitter, simply writing #notguilty.
Little is due to be sentenced later.
The judge said he was not considering an “immediate custodial sentence” due to the “wholly exceptional” circumstances faced by Mrs Little, whose husband is terminally ill.
Mr Mackinlay’s agent Nathan Gray was acquitted on 13 December.