"At present, there is no overview on the citizenship of immigrants in 2019, but based on 2018 [figures], it is projected that most of the net immigration balance consisted not of Estonian citizens but of citizens of other countries," Solman said, reacting to preliminary data from government agency Statistics Estonia which showed a net immigration figure of over 5,000 for 2019.

The Statistics Estonia data recorded 12,240 people arriving in Estonia, and 7,210 leaving the country, in 2019.

This figure is provisional and does not include unregistered migration.

Solman also pointed to 2018's figures, saying non-Estonian citizens accounted for over 80 percent of net immigration that year.

Over 9,700 people entered Estonia in 2018 who were non-citizens, compared with around 7,800 who held citizenship, Solman said.

At the same time, whereas over 6,500 Estonian citizens left the country in 2018, close to 4,000 non-Estonian citizens left.

"To maintain population balance, Estonia has set itself an immigration limit of 0.1 percent of Estonia's permanent population, or slightly more than 1,300 people per year," Solman said, noting that the coalition government already has changes on the table to address the issue – as noted net immigration was already around four times that of the 1,300 figure cited by Solman, regardless of the origin of those migrating into the country.

Solman also claimed that temporary residence and short-term employment had risen in Estonia, particularly among Russian and Ukrainian citizens – these groups had seen around a 25 percent rise on year to 2019 (though "undefined citizenship" makes up the third-largest group at 17 percent-ed.).

Solman, who has made efforts to encourage a growth in Estonia's birth rate among its citizens, also noted that the relative population of 'native' Estonians will also decline, if current trends continue.

"According to Statistics Estonia's population projection last year, the country's population will decrease slightly, due to a negative natural increase," Solman said, referring to birth versus death rates among Estonian citizens.

"Until more people are born than die, Estonia will not be sustainable," she added.

"Due to immigration, the proportion of Estonians within the population has been decreasing for several years;this primarily affects the main immigration destinations, especially Tallinn," she added.

According to the preliminary data of Statistics Estonia, on January 1, 2020 the Estonian population was 1,328,360 , a rise of 3,540 on year.

Among those nationalities holding long-term residence permits in Estonia, Russian citizens made up overwhelmingly the highest proportion, with over 80,000, compared with the next-highest group (Ukrainians at a little over 4,000). However, those of "undefined citizenship" numbered over 70,000, according to Statistics Estonia.