The prosecutor's office has requested Center Party MP Mailis Reps' parliamentary immunity be waived, ahead of a criminal trial on corruption charges.
Prosecutor's office spokesperson Kairi Küngas told ERR: "We are preparing to send the application to the Chancellor of Justice."
As an MP, this would need to happen before the case could go to trial.
Defense counsel for Reps, Paul Keres, said his client had no comment on the matter.
"Mailis Reps has made it quite clear that she does not want to comment on this criminal case to the media, and I will proceed on that basis," Keres told ERR on Thursday.
Reps will not be running in next month's local elections.
The prosecutor's office says it had not received any requests not to waive Reps' parliamentary immunity by the deadline for doing so this week, and is going ahead with its request to the Chancellor of Justice to do just that.
If the justice chancellor, Ülle Madise, grants her consent to this request, the chancellor must then put the proposal to the Riigikogu.
A majority at the 101-seat chamber must vote in favor of the request for Reps' immunity to be waived.
In addition, the education ministry itself has filed a civil suit against Reps, claiming damages in respect of alleged misuse of the public purse.
Defense counsel can make further pre-trial requests to the prosecutor's office, once the criminal case file has been submitted. Such requests might include questioning other witnesses or submitting other evidence, ERR reports.
Reps resigned from her position as Minister of Education and Research last November after media reports emerged that she had allegedly used a ministry car for non-work purposes, including the school run and also a family trip to Croatia.
Other allegations which followed included the personal use of a coffee machine, and a birthday party at an upscale Tallinn restaurant, both on the public purse.
Reps was Center's chief negotiator in coalition talks with the Reform Party ahead of the two parties entering office together in late January, but remains an MP. Government ministers do not sit at the Riigikogu.
Editor: Andrew Whyte