A Tory Party activist has told a court she did not breach spending limits to help defeat UKIP's Nigel Farage in South Thanet in the 2015 election.
Marion Little, 63, from Hertfordshire, was said to have effectively run the Kent campaign for Craig Mackinlay MP.
Ms Little, of Ware, said while the seat was considered important, she did not create or falsify documents.
She denies three counts of intentionally encouraging or assisting an offence, at Southwark Crown Court.
Mr Mackinlay, 52, of Ramsgate, denies two charges of making a false election expenses declaration under the Representation of the People Act 1983.
Tory aide Nathan Gray, 29, of Hawkhurst, denies one count of the same charge.
Giving evidence, Ms Little said: "[The South Thanet seat] was top of the list [of Conservative priorities].
"It was a very important seat because of all the media Mr Farage had gathered."
She told the court how "all the hoardings" in South Thanet in the run-up to the election appeared to have a UKIP poster on them, often featuring Mr Farage's face.
Questioned by defence counsel Jim Sturman QC about the issue of falsifying documents relating to expenses, Ms Little replied: "I would never do anything like that."
She said: "I have never falsified or knowingly done anything like that."
Prosecutors previously suggested that Mr Mackinlay, Mr Gray and Ms Little deliberately submitted "woefully inaccurate" expenditure returns.
Prosecutor Aftab Jafferjee QC told jurors it became a "two-horse race", which was won by Mr Mackinlay with a majority of about 2,800 in an electorate of 70,000.
He said: "In those pre-referendum days, UKIP were on the rise and the threat perceived by the Conservative Party to their share of the vote only intensified in the lead-up to the 2015 election."
The trial continues.