Conservative MP Craig Mackinlay has been cleared of offences over his 2015 general election victory.
The 52-year-old, from Ramsgate, Kent, was found not guilty by a jury at Southwark Crown Court of two charges of making a false election expenses declaration.
On the court steps, Mr Mackinlay told reporters: "It has been nearly three years of pure hell – for my family particularly.
"But I've got real thanks to the people of South Thanet. They knew I was charged with this offence just six days before the election of 2017 and they still supported me."
He added: "They supported me and I'm going to fight even harder for them in the future."
Mr Mackinlay, the South Thanet MP, defeated ex-UKIP leader Nigel Farage by 2,812 votes to win the parliamentary seat in 2015.
The Kent constituency was one of the most fiercely-contested of that year's general election, which saw the Conservatives win a slim House of Commons majority.
During the campaign, South Thanet was visited by a number of high-profile Conservative figures, including Theresa May, Boris Johnson, George Osborne and ex-footballer and activist Sol Campbell.
A trial centred on claims hotel costs and other expenditure for Tory activists and party workers were recorded as national election spending rather than local constituency spending.
It was alleged this was to ensure strict electoral spending limits were not breached.
Mr Mackinlay said: "It's been a dreadful time. I think there are questions that need to be asked of the electoral law and the Electoral Commission needs to get together with the political parties to make sure that never again a candidate or an agent can be accused of these things because these are serious accusations that would be life-changing if convicted of them."
Senior Tory party worker Marion Little, 63, was found guilty of two counts of intentionally encouraging or assisting an offence under the Serious Crime Act 2007.
She was cleared of a third count of the same offence.
Tory aide Nathan Gray, 29, of Hawkhurst, Kent, was previously cleared of making a false election expenses declaration.
He worked as an election agent for Mr Mackinlay in 2015 and was found not guilty by a jury in December after several days of deliberations.
During the trial, Mr Mackinlay was alleged to have "simply abandoned" expenditure rules to win the South Thanet seat.
The jury were told the accused had been warned by Tory colleagues the campaign was "perilously close" to breaching spending limits and he and the others faced a "real prospect of a legal challenge from Farage" if they erred.
The declared spending on Mr Mackinlay's South Thanet campaign came in under the £52,000 limit set for each constituency.
But, prosecutors claimed about £60,000 spent on staffing, accommodation, advertising and other costs was not declared.
More from Politics
Mr Mackinlay was re-elected in South Thanet at the June 2017 snap general election with an increased majority – a week after he was charged with alleged overspending.
The Conservative Party was previously fined a record £70,000 over "significant failings" in the way spending was reported during the 2015 election campaign, including South Thanet, and three by-elections in 2014.