THE Conservative party has been fined £15,000 following an investigation into by-election campaign expenses in Clacton.

A probe into the 2014 by-election triggered by Douglas Carswell's defection to Ukip revealed "significant failures" by the party to report accurately on how much it spent on campaigning.

The investigation looked at Tory spending in three by-elections in 2014 and at the 2015 general election.

Douglas Carswell secured a landslide victory against Giles Watling in the Clacton by-election.

The Electoral Commission said the Conservatives declared a total election spend of £84,049.22.

In a parliamentary by-election, each candidate has a spending limit of £100,000.

But the commission found there were "significant failures" by the party to report accurately how much it had spent on things such as accommodation for staff and volunteers working for the campaign.

The Tories spent £6,582.86 for 71 nights at Clacton's Premier Inn between September 9 and October 1.

The party also paid an unknown sum for 290 nights at the Lifehouse Spa in Thorpe-le-Soken between September 4 and October 11.

The Conservatives said a formula was used to work out how much had been spent on local campaigning.

But the commission said "the absence of records of this formula make it impossible to establish how the amounts invoiced by the Party to each of the three candidates and agents were calculated" and that the invoices were "likely to be inaccurate".

In total the Conservative party was fined £70,000 following the investigation into the three by-elections and general election.

The commission said the party "failed to maintain records explaining the amounts it invoiced to candidates in three 2014 by-elections, for work on their campaigns. Therefore the accuracy of the amounts could not be verified".

Electoral Commission chairman Sir John Holmes said: “Our investigation uncovered numerous failures by a large, well-resourced and experienced party to ensure that accurate records of spending were maintained and that all of the party’s spending was reported correctly.

"The rules established by Parliament for political parties and their finances are there to ensure transparency and accountability. Where the rules are not followed, it undermines voters’ confidence in our democratic processes, which is why political parties need to take their responsibilities under the legislation seriously.”