The party failed to accurately report a donation and keep a proper accounting record following an investigation into how the refurbishment was financed.

The investigation found that the party failed to fully report a donation of £67,801.72 from Huntswood Associates Limited in October 2020, which included £52,801.72 connected to the costs of refurbishment to 11 Downing Street.

The full value of the donation was not reported as required in the party’s Q4 2020 donation report.

The Electoral Commission also concluded that the reference in the party’s financial records to the payment of £52,801.72 made by the party for the refurbishment was not accurate.

The investigation found that decisions relating to the handling and recording of this donation reflected serious failings in the party’s compliance systems.

Louise Edwards, director of regulation at the Electoral Commission, said: “Our investigation into the Conservative Party found that the laws around the reporting and recording of donations were not followed.

“We know that voters have concerns about the transparency of funding of political parties. Reporting requirements are in place so that the public can see where money is coming from, inaccurate reporting risks undermining trust in the system.

“The party’s decisions and actions reflected serious failings in its compliance systems. As a large and well-resourced political party that employs compliance and finance experts, and that has substantial sums of money going through its accounts, the Conservative Party should have sufficiently robust systems in place to meet its legal reporting requirements.”

For the offence of failing to accurately report the full value of the donation from Huntswood Associates, the Commission imposed a sanction of £16,250. For contravening the requirement to keep proper accounting records, a sanction of £1,550 has been imposed.