The investigations into the Conservative Party’s battle bus campaign in the 2015 contest have examined whether strict spending limits in target seats were breached.
Meanwhile, Colchester’s Will Quince revealed that he had been interviewed by police - the second Tory MP known to have been quizzed by officers investigating election expenses.
Mr Quince said he had been told by Essex Police he faced no further action after voluntarily attending an interview under caution last January. Essex Police is not one of the forces that has submitted files to the CPS.
But a CPS spokesman said it had received files from: Avon & Somerset, Cumbria, Derbyshire, Devon & Cornwall, Gloucestershire, Greater Manchester, Lincolnshire, the Metropolitan Police, Northamptonshire, Nottinghamshire and West Yorkshire police.
Once it has received a file, the CPS will decide whether to charge anyone. The files were “all under consideration”, a spokesman said.
A 12th force - Staffordshire - said it had also sent a file to the CPS. In a statement posted on his Twitter feed, Mr Quince welcomed the decision by Essex Police but said the complaint against him had been “vexatious and politically motivated”.
The disclosure follows reports that Craig Mackinlay, who fought off a challenge from former Ukip leader Nigel Farage to hold Thanet South for the Tories, had been questioned for six hours last week by Kent Police.
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.
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.
However, he said that the inquiry has caused stress to his staff and family and he had suffered “reputational damage” while it was carried out.
“Moving on to the allegation itself, I consider this to have been vexatious and politically motivated,” he said.
“Politics is not a game. I would ask those individuals to think about the cost of this investigation, the important work those police officers could have instead been doing over this lengthy period, the stress that it put me, my family and my team under and the reputational damage to me personally.”
Other MPs have directed their anger at Conservative Campaign Headquarters, complaining that they had been cut adrift by the party’s high command even though the complaints relate to the busing of activists to campaign in key marginal seats, which was organised centrally. The allegations centre on whether the “battle bus” tour should have been recorded as counting towards individual candidates’ spending limits, rather than as part of the larger national spending return.
In a leaked email to Conservative Party chairman Sir Patrick McLoughlin, Lincoln MP Karl McCartney complained they felt “completely cast adrift” and had been “left to fend for themselves”. In a statement, Mr McCartney said he had made clear his “forthright views” privately to a number of senior party figures on behalf of backbenchers.