On Saturday, they met in secret.
On Sunday, they made their move.
Following instructions by their party leader Kemal Kılıçdaroğlu, 15 MPs from the main opposition CHP announced their immediate resignation and joined Meral Akşener’s Good Party, a burgeoning centre-right rival.
This was not an act of political fratricide on the eve of Turkey’s snap election campaign, but a calculated move by both leaders.
Indeed, the 15 MPs are likely to be rewarded with prime spots in the CHP’s candidate lists for 24 June.
But by being Good Party members for the next week, they raise that party’s tally to 20 MPs – enough to form a group in parliament and, crucially, ensure it is permitted to field its own candidates in the election.
The minyan appears to have worked: Turkey’s election commission, the YSK, duly announced that the Good Party could take part in June’s election.
It’s unlikely that the mass resignation, which carried all the drama of a publicity stunt, was alone responsible for that announcement.
Ms Akşener’s outfit has run a blaring campaign ever since Recep Tayyip Erdoğan announced the snap election last week to warn the YSK against finding a reason – such as the party’s youth – to exclude it.
What Sunday’s stunt made clear is what the tone of the forthcoming campaign will be.
Ms Akşener hailed Mr Kılıçdaroğlu for his “historic democratic stance”. The governing AK Party alauded to how the CHP toppled a centre-right government in 1977 by convincing twelve MPs to switch parties, but as attempts to disparage it go it was fairly weak.
The fact is this is a battle that AK and the nationalist MHP, its de facto junior coalition partner, has lost. Excluding the Good Party from the election was never going to be justifiable, not least with claims that the YSK is acting independently.
For all its drama, the CHP-Good Party stunt is complicated, boring and will barely resonate with the voting public.
But it will feed into the opposition’s narrative of injustice as it tries to convince voters to turn against Mr Erdoğan.
If this stunt is a sign of further collaboration among Turkey’s disparate opposition parties in the coming days, this election could become more competitive than we thought.