Greater Manchester Police are one of twelve police forces across the country to have send files to the Crown Prosecution Service over allegations over election expenses.
The allegations come after complaints about the way Conservative “battle bus” visits to constituencies had been recorded in campaign spending returns and follow an investigation by Channel 4 News into claims the party may have broken election law at the 2015 general election and three earlier by-elections.
The allegations range around whether strict spending limits in target seats were breached during the Conservative campaign in the 2015 election.
A CPS spokesman said it received files from the following police forces: Avon and Somerset, Cumbria, Derbyshire, Devon and Cornwall, Gloucestershire, Greater Manchester, Lincolnshire, Metropolitan, Northamptonshire, Nottinghamshire and West Yorkshire.
Senior figures in the Conservative party fear that the investigation outcome could void votes in a number of areas, triggering by-elections. Individuals in the party could also face criminal charges.