Kent Police has been granted more time to probe allegations about Conservative election expenses in South Thanet at the general election.

A judge has ruled there was a case for an extension because of the exceptional circumstances involved and there was a very significant public interest in the claims, first made by Channel 4 news, being investigated.

The allegations concern whether spending limits had been breached in South Thanet and were not properly recorded by the Conservative party.

The ruling by district judge Justin Barron follows a hearing at Folkestone Magistrates court today.

In his conclusions, Mr Barron said: “The combination of circumstances before me is wholly exceptional and goes far beyond the usual circumstances that would exist in a typical case where election expenses are being investigated.”

There was “very significant public interest in the matter being fully investigated,” he added.

“The consequences of a conviction would be of a local and national significance with the potential for election results being declared void.”

Timothy Straker QC, who represented Kent Police argued that the allegations warranted an extension to the time limit to investigate them further.

“We have here a circumstance that is exceptional in an election...we have an allegation of national funds being used - in what some might put it - to buy an election.”

“What could be more exceptional than one party defeated by another using national funds contrary to law?”

The efforts made by the Conservative party to beat Nigel Farage, the leader of UKIP, was itself “an exceptional circumstance, he said.

There had been no undue delay by Kent Police, he added.

James Laddie QC who represented the Conservative MP Craig Mackinlay and his agent at the hearing, said Kent Police had not proven there were exceptional reasons for an extension.

He told the court it was “grossly overstating the position that one cannot imagine that this is as serious as it gets.”

There was no evidence to suggest that the election had been “bought” and the result in South Thanet would have been the same, he argued.

He acknowledged that while there was a public interest “it is not for the court of public opinion to justify exceptional circumstances.”

Kent Police had failed to act without “undue delay” on the allegations as the law required for an extension to the time limit, he added.

“There is no getting away from the fact that there has been no investigation [by Kent Police] at all.”

Under electoral law, inquiries into such allegations are normally expected to be completed within 12 months of a poll. However, the law also allows for extensions to this where there are exceptional circumstances.

The allegations, first raised by Channel 4 news, focus on whether the costs of bringing in Conservative activists by bus and hotel accommodation should have been recorded as local election spending or national.

Under electoral law, inquiries into such allegations are normally expected to be completed within 12 months of a poll. However, the law also allows for extensions to this where there are exceptional circumstances.