The country’s troubled coalition appeared set for more turmoil on Monday after its junior partner expelled two lawmakers for aligning themselves with leftist opposition SYRIZA by calling for PASOK leader Evangelos Venizelos as well as ex-Finance Minister Giorgos Papaconstantinou to be investigated by Parliament for their handling of the Lagarde list of Greeks with deposits in a Swiss bank.

In a letter to Parliament Speaker Evangelos Meimarakis, Democratic Left chief Fotis Kouvelis said the two deputies, Odysseas Voudouris and Paris Moutsinas, had repeatedly strayed from the party line. Earlier in the day, Voudouris and Moutsinas had backed SYRIZA’s position on the Lagarde list.

SYRIZA’s proposal, submitted to Parliament on Monday evening, called for Venizelos and Papaconstantinou to face investigation on criminal charges and added that former Prime Minister George Papandreou and current Premier Antonis Samaras should bear varying levels of political responsibility for the affair.

Kouvelis’s move meanwhile left the coalition with just 164 MPs. Sources close to Samaras said they weren’t worried that the reduced majority could have an impact on two secret ballots to be held next Monday or Tuesday – one on the coalition’s proposal for a committee to be set up to probe Papaconstantinou and the other on SYRIZA’s proposal for a committee to investigate both Papaconstantinou and Venizelos. The fact, however, that the votes are secret could lead to some skeptical MPs embracing SYRIZA’s proposal for Venizelos to be put on the spot.

Depending on the vote results, a committee or committees – each comprising 12 or 13 MPs – will be established and will have between 30 and 40 days to probe the minister or ministers. After this, Parliament will be called on to vote on whether to impeach one or two former ministers for breach of duty.

On Wednesday, prosecutors investigating the Lagarde list affair are expected to hear the explanations of the three relatives of Papaconstantinou whose names were removed from the original list, prompting the coalition to seek a parliamentary probe into his actions.