The Reform Party is submitting a vote of no-confidence in interior minister Mart Helme (EKRE) on Monday.
The motion, which has collected 45 signatures, will be handed in to the Riigikogu session, which began on Monday at 3 p.m..
"There are currently 45 signatures on the motion of no-confidence, [from] the Reform Party, the Social Democratic Party and Raimond Kaljulaid," said Reform leader Kaja Kallas, ERR's online Estonian news reports.
Reform and the Social Democratic Party (SDE) form the opposition, with a total of 44 seats. Raimond Kaljulaid is an independent, who quit the Centre Party in early April, citing opposition to the ongoing talks between Centre and the Conservative People's Party of Estonia (EKRE).
"We are also in contact with members of the coalition, to see if we can get support from there also," Kallas added.
The party started the process of drawing up the no-confidence motion in mid-May, publishing the text a few days later.
The motion's main grievances concern damage the party says Mart Helme, who is also EKRE leader and deputy prime minister, has done to Estonia's reputation both before and after entering office, as well as insults made to various social groups, plus allegations of dishonesty.
Reform also added to the litany a violation it says Helme committed on election day, in calling on people to vote for his party. EKRE won 19 seats at the general election on March 3, nearly three times the number it held at the previous Riigikogu.
"The police initiated proceedings against Mart and Martin Helme for violation of § 168 of the Penal Code, and have already issued a precept concerning the radio program, where the prohibited activities took place. The interior minister has not regretted this violation," Kallas continued.
The Police and Border Guard Board (PPA) launched an investigation last week to determine whether "Räägime asjast," a broadcast by Mart and Martin Helme aired on TRE Raadio, constituted unlawful campaigning on election day, and thus a breach of the Penal Code .
"Regarding the minister [Mart Helme], who is so careless when it comes to laws and ethics, the Estonian state cannot have any confidence in him, and in fact he should resign. Since Mart Helme is not going to do this, we wish to express our lack of confidence in him," Kallas concluded.
The no-confidence motion only needed 21 votes to be put to the Riigikogu in any case, but must get a majority of at least 51 votes at the 101-seat parliament for its demands to be put into action. This means that the opposition requires at least six MPs from the three coalition parties to vote in its favor, and against their own government.
A vote can be made at the earliest on the second day after a no-confidence motion's submission, unless the government requires a faster decision. Should the no-confidence motion fail to pass at the Riigikogu, under Estonian law a minimum of three months must pass, before a new motion can be submitted.
Editor: Andrew Whyte