Giles McNeill, 39, who was Conservative leader of West Lindsey District Council and an electoral agent for long-serving Conservative MP Sir Edward Leigh, admitted eight theft, fraud and forgery offences totalling £29,770.
Lincoln Crown Court heard McNeill paid dozens of fraudulent cheques into his own bank account and kept members’ payments from 22 party fundraising events over a five-year period.
This included paying more than £4,000 meant for constituency association coffers into his own bank account the day after Boris Johnson was guest speaker at a Tory party fundraiser in March 2018.
Andrew Scott, prosecuting, said McNeill was paid £450 a month to act as the Organising Secretary for Gainsborough Constituency Conservative Association from 2010.
He also held other senior roles with the Lincolnshire Area Conservative Association and the West Lindsey District Council Constituency Conservative Association.
Mr Scott said: “Over a period of six years, between 2014 and 2020, he defrauded the local Conservative associations and individual members out of almost £30,000.”
In total, McNeill admitted the theft of £9,365 from the Conservative Party.
Mr Scott said McNeill also made out 93 cheques on which a signature was forged.
This included 35 cheques relating to a loss more than £8,500 to the Gainsborough Constituency Conservative Association, and 25 cheques relating to a loss of over £4,600 to the West Lindsey District Council Constituency Conservative Association.
McNeill also admitted making credit transfers into his own account from the Gainsborough Constituency Conservative Association and setting up a PayPal account to siphon off over £2,000 from the organisation.
The court heard McNeill’s actions began to be uncovered when Tracey Coulson succeeded McNeill’s brother as the treasurer of Gainsborough Constituency Conservative Association in 2019.
It was discovered cheque payments for the association’s Market Rasen office had bounced and when McNeill resigned as Organising Secretary in August 2020, Miss Coulson found the accounts “in a mess.”
Miss Coulson discovered McNeill had applied for an “inappropriate” Covid recovery grant of £10,000 from the Treasury which hid other holes in the accounts.
She was also unaware of a £6,000 loan obtained by McNeill from Conservative Central Office.
In a victim impact statement, Miss Coulson said McNeill’s actions had caused huge reputational damage to the party.
During interview, McNeill admitted he began gambling in 2013 and this became acute by 2016 - but he also insisted others were happy for him to “do the donkeys work” and not to take any responsibility.
Hal Ewing, mitigating, said references from his fellow councillors, and MP Sir Edward Leigh, for whom he worked closely, made it clear he was a hardworking and talented politician.
“He went into politics for the best of motives,” Mr Ewing said.
McNeill, of The Chestnuts, Nettleham, admitted one charge of theft from the Conservative Party, one charge of using a false instrument, and six charges of fraud by abuse of position.
Passing sentence, Judge John Pini QC told McNeill his fall from grace had been steep.
The judge said: “If the electorate can not trust those elected then politics breaks down.
“Your conduct was a gross breach of trust over a number of years.”
McNeill was leader of West Lindsey District Council from May 2019 to September 2020, when he announced he was stepping back from the role for “personal reasons”.
He also left his role as communications manager for Gainsborough Conservative MP Sir Edward Leigh.
He remained a sitting councillor for the Nettleham ward until his resignation last month.
Speaking after the sentencing, Detective sergeant Mike Head from Lincolnshire Police said: “This was a complex investigation due to how McNeill handled the associations’ finances which allowed his offending to go on for so long before it was identified by those working alongside McNeill.”