The DUP was slapped with two £500 fines for filing inaccurate quarterly loans reports, which it has now paid.

The TUV was fined £1,000 for the late delivery of its spending return for the 2017 UK general election, but has not yet paid the fine.

The sanctions have been published in the latest of the electoral watchdog’s monthly investigations updates.

Ann Watt, head of the Electoral Commission in Northern Ireland, said: “The reporting requirements are clear, so it is always disappointing when parties fail to comply. It’s vital that voters are given an opportunity to see accurate and full reportable data on what parties spend money on in order to influence them at elections and referendums.

“This provides transparency in the political finance system and is open for anyone to scrutinise. The Commission will continue to enforce these requirements on all parties and campaigners to ensure voters have the information they need.”