"We are also communicating with both Centre other parties to prevent this coalition,'' said Ms Kallas at a press conference at Reform's headquarters on Tuesday afternoon, noting that she did not see last week's rejection by Centre of partnership with Reform as the end of the matter.

She did however note that any partnership with Centre was to be on an equal footing, which meant both an equal fulfillment of electoral promises, and an equal division of ministerial portfolios, and stated that any implication that she had seen a Reform-Centre deal as an unequal coalition had been a misunderstanding.

''It seems to me that Centre's members have not been given the full picture,'' she said, referring to its decision to hold talks with teh Conservative people's Party of Estonia (EKRE), as well as Isamaa, follwing the Reform-Centre impasse at the end of last week.

''We are currently open to all parties, except EKRE,'' she added. That Reform would not make a deal with EKRE was a statement repeated several times before, during and after the 3 March general election, where EKRE picked up 19 seats.

Estonia's image needs rescuing

Ms Kallas also stressed that Estonia's image needed to be rescued, probably referring to the fact that EKRE is a far-right party whose recent parliamentary gains have attracted the attention of the international media.

''When Mart Helme pulls out eight ''fat'' lines, noone has a problem, but if I say there is just the one red line, then it's a diferent story,'' she said, referring to the ostensible sticking point between Reform and Centre – the €500 monthly tax-free threshold – and the various differences EKRE will have with Centre.

However, Ms Kallas was sanguine about the one party which had made overtures to Reform, the Social Democratic Party (SDE).

''We are grateful to the SDE, but unfortunately we can't make a coalition just with them,'' she said. With only 10 seats plus Reform's 34, such an alliance would still be seven seats short of the required 51 for a Riigikogu majority. A Centre-EKRE-Isamaa coalition would have 57 seats. A Centre-Reform lineup would comprise 60.

Another issue with this two-party coalition would be who would be Prime Minister. In the normal run of things it would be Kaja Kallas as leader of the biggest party by seats, which would mean Jüri Ratas relinquishing the role, which he has served in since November 2016.

The Centre-EKRE-Isamaa talks entered their second day on Tuesday.