Ukip opens candidate nominations in South Thanet after Conservative spending scandal

The inquiry, he said, could lead to election results "being declared void".

The Conservative Party has complied fully with the Electoral Commission's investigation since it began more than a year ago and will pay the fines they have imposed.

Files from 12 police forces relating to election expenses have been passed to the Crown Prosecution Service.

Electoral Commission chairman Sir John Holmes said parties' failure to follow spending rules "undermines voters' confidence in our democratic processes".

The probe centres around hotel bills for Tory aides campaigning for Mr Mackinlay whether or not they should have been included in his official spending return.

The party faces claims that accommodation costs of activists bussed into key constituencies around the country should have been recorded under individual candidates' limits, rather than as part of the national campaign.

In a statement to the Evening Standard, the Metropolitan Police said it had received four complaints and detectives had been given a special time extension to investigate one because of "exceptional circumstances". Mr Quince said he had voluntarily attended an interview under caution at a police station in January.

Mr Morris told BBC's Newsnight: "We were all given an email, every one of us had the same email from Mark Clarke at the time who was running the battle bus project, saying it was a national spend". The Labour Party and Liberal Democrats both failed to declare sums of money which constituted a larger proportion of their national expenditure in the 2015 general election.

It was reported yesterday that Thanet South Conservative MP Craig Mackinlay was questioned by Kent Police for six hours over claims of inaccuracies in his constituency election expense returns.

Some cases have been investigated and concluded with no further action.

In his statement, Mr Quince acknowledged that once a formal complaint had been made in June 2016, police had a duty to carry out a thorough investigation.

The Conservatives argue that they based their national anti-Ukip campaign in Thanet because Mr Farage and his party's national campaign did so.

The latest moves come amid growing anger among Conservative MPs still facing investigation by the police and the Electoral Commission in relation to spending during the 2015 election.

The Tories have responded to the fines by suggesting there needs to be a review of how the Electoral Commission's processes and requirements could be clarified or improved.

Although they are not named in the report, the advisers have previously been reported to include Theresa May's current chief of staff Nick Timothy, who was an adviser to her in the Home Office.

  • Elsie Buchanan