The investigation, which followed Channel 4 News' own investigation into claims that Tories may have broken election law at the 2015 general election and three earlier by-elections, found:

  • The Conservative Party's 2015 UK Parliamentary general election spending return was missing payments worth at least £104,765
  • Separately, payments worth up to £118,124 were either not reported to the commission or were incorrectly reported by the party
  • The party did not include the required invoices or receipts for 81 payments to the value of £52,924
  • The party failed to maintain records explaining the amounts it invoiced to candidates in three 2014 by-elections, for work on their campaigns