Kent Police has submitted its file to the CPS following an investigation into Conservative Party expenses during the 2015 General Election.
Last month South Thanet MP Craig Mackinlay was questioned for several hours under caution by police officers investigating the election overspend allegations.
The police probe was launched following a Channel 4 investigation which questioned the local election spend during the Conservative campaign.
The legal expense limit for South Thanet for that time-frame was £15,016.38. The Conservatives’ local expense declaration was for £14,837.
But a bill of more than £18,000 for stays in two isle hotels and a hostel was not included on local expenses but attributed to national spending. This figure would have taken the party over the legal campaign limit.
Last year Kent Police won a court hearing to have a 12 month extension to investigate the claims.
Mr Mackinlay had contested the move but was defeated.
A Kent Police spokesman said: “Officers investigating offences under the Representation of the People’s Act 1983 submitted a file to the Crown Prosecution Service on 18 April.”
The CPS will now make the decision of whether to prosecute or not.
Mr Mackinlay won the South Thanet seat with just over 2,000 more votes than his nearest rival, former Ukip leader Nigel Farage.
Mr Mackinlay took 38% of the votes – 18,838 ballots.
The penalties for wrongly declaring local elections include the possibility of a year behind bars. If proven it also means the General Election results can be declared void – triggering a by-election.
Multiple police forces are investigating around 30 MPs in relation to irregularities in election campaign expenses.