The Conservatives have been handed a hefty fine of £70,000 by the Electoral Commission after failing to declare expenses made in the General Election accurately - plunging the party further into crisis.
The elections watchdog said there had been "numerous failures" in how the Tories reported expenses in the 2015 campaign, as well as in three 2014 by-elections.
The commission found a spending return made by the Tory party for the election was missing payments totalling an estimated £104,765.
It also found the party hadn't included receipts or other such records for 81 payments worth over £50,000, and didn't have records relating to invoices in three by-elections.
Essentially, this meant the accuracy of the spending return was in question and unable to be verified.
Sir John Holmes, chairman of the Electoral Commission, said this failure to follow the rules "undermined voter confidence."
He said: "Our investigation uncovered numerous failures by a well-resourced and experienced party to ensure maintainence of accurate records of spending.
"The rules established by Parliament are there to ensure transparency and accountability.
"Where they aren't followed, it undermines voters' confidence in our democratic processes."
He warned there was a present risk of political parties seeing the commission's fine merely as a price to be paid for "doing business."
The Tories are still reeling from the debacle over National Insurance, which saw Chancellor Philip Hammond forced into a humiliating climbdown yesterday.
Mr Hammond had announced a hike in NI contributions for self-employed workers in last week's budget but scrapped the policy yesterday after intense pressure from MPs and the media. A Tory source has said he is now "on probation" as chancellor.