CAMPAIGNERS have won a High Court challenge against the Electoral Commission over election spending by Vote Leave in the run-up to the EU referendum.

The Good Law Project[GLP] brought a judicial review against the elections watchdog, arguing it had failed in its duty to regulate the referendum process ahead of the historic vote in June 2016.

In a ruling today, Mr Justice Leggatt said the Commission had "misinterpreted" the definition of referendum expenses in relation to the Vote Leave campaign.

He said Vote Leave paid £620,000 to Canadian online advertising firm AggregateIQ[AIQ] at the request of another leave campaigner, Darren Grimes, in the days before the referendum.

This put Vote Leave over its £7 million election spending limit by almost £500,000.

GLP launched the case in October last year after the Commission concluded there were "no reasonable grounds to suspect" any incorrect reporting of campaign spending or donations by Vote Leave.

However, the watchdog later opened an investigation into the spending of Vote Leave and Mr Grimes and concluded in July that both had incorrectly reported their spending.

Vote Leave was fined £61,000 and Mr Grimes was handed a £20,000 fine by the Commission, which referred the matter to the Metropolitan Police.

The judge said the Commission's findings were made on a different legal basis so the High Court proceedings remained relevant.

Sitting with Mr Justice Green, Mr Leggatt said: "We see no reason to doubt that the payments were, as they were said to be, donations made by Vote Leave to Mr Grimes to meet referendum expenses, which he incurred by purchasing advertising services from AIQ.

"But it is also clear that, on the proper interpretation of the statutory provisions as we have analysed them, Vote Leave 'incurred expenses' by making the payments, that those expenses were incurred in respect of advertising and that the expenses were incurred 'for referendum purposes'.

"They were, therefore, 'referendum expenses'."

The judge said there would be a further hearing to determine what orders the court should make as a result of its ruling.

Earlier this week, the SNP’s Deidre Brock raised the issue of AIQ at Prime Minister’s Questions when she questioned Theresa May about why Jeff Silvester and Zack Massingham – co-founders and business partners of the company – had visited No 10 last autumn.

The PM promised to give a response in due course.

Later, Ms Brock, who represents Edinburgh North and Leith, urged her to “come clean over Downing Street’s shady meetings with AIQ”.

“Not recording a visit in the transparency data register is a serious breach of the rules and we must now be told what lies behind this. Invitations to Downing Street are not offered on a whim - Theresa May must come clean,” said the SNP MP.