ELECTORAL Commission bosses have revealed their frustration at being gagged over the shadowy Constitutional Research Council (CRC).

At a meeting of the Commons' Digital, Culture, Media and Sport Committee, the watchdog said they were unable to provide more information on the CRC's substantial donation to the DUP in the run up to the Brexit referendum.

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The CRC is fronted by former senior Scottish Tory, Richard Cook, who is based in East Renfrewshire.

In early 2017 they donated £435,000 to the DUP, who then spent nearly £300,000 of that on a wrap-around pro-Brexit supplement for the Metro newspaper, which is only available in England, Scotland and Wales.

Until recently in Northern Ireland, strict rules from the days of the Troubles meant donors to local political parties did not have be named.

Although MPs voted to reform those laws, the Tories, whose minority government is propped up by the DUP, ignored pleas by the Commission to backdate the changes to 2014, instead keeping details of any donation before July 1, 2017, secret.

On Tuesday, the SNP's Brendan O’Hara asked the Commission if they had investigated “why an unincorporated body in Scotland gave the DUP almost half a million pounds that was then used in the referendum campaign to advertise in a newspaper in London?”

Claire Bassett from the Electoral Commission said the law meant she was “restricted” in what she could say.

“We are frustrated by the decision not to take this back to 2014, which would have allowed us to be much more transparent,” she added.

Louise Edwards from the Commission said the DUP was required to file quarterly reports, which they did, and that they verified them: “If we find that donors on the reports were impermissible, then we can then talk about them. We cannot talk about them, because the donors were permissible.”

“We are trying to get the truth and we are obstructed,” O’Hara added.

Earlier the Committee heard from Elizabeth Denham, the information commissioner, on a new report detailing a series of fines issued by the data watchdog, including a £135,000 hit on Arron Banks and his companies.

According to the ICO, Banks, who was behind the Leave.EU campaign had used data from his Eldon Insurance company to send £330,000 in pro-Brexit marketing in the run-up to the EU referendum.

The ICO also warned that the businessman and his firm, which trades as Go Skippy, faced fines of £60,000 each for sending of more than one million emails to Leave.EU subscribers which included GoSkippy marketing material.

In its final report on the use of data analytics in political campaigning, the ICO also disclosed that it would have issued Cambridge Analytica – the company at the centre of the Facebook data breach – with a “substantial fine” if it had not gone into administration.

However, the watchdog also cleared the official Vote Leave campaign over a number of allegations, including claims of “unlawful processing of UK personal data”.