Tunisia's ruling coalition partners brace for divorce

"We didn't expect that a divide in positions with regard to the premier's departure could cause such a rupture," said Ridha Driss, a member of Ennahdha's executive office.

"We still believe that cooperating with the head of state and all the parties is a national need. Our idea of consensus is an inclusive one - we are ready to work with everyone without exception."

Hamza Meddeb is a research fellow at the European University Institute's Middle East Directions Programme. The odd alliance between secularists and Islamists, he says, "was built on a consensus conceived to allow mutual neutralisation of the two camps, not a collaborative consensus that would enable the coalition to build institutions and implement reforms". It was a tactical alliance, in other words.

In his view, the Islamists intend to revive and pursue a compromise with the secularists to avoid being isolated politically, while keeping the democratisation process on track. Their priorities, the researcher explained, are setting an agenda in preparation for 2019 parliamentary and presidential polls, and having a say in the election of the next prime minister.

Facing this renewed polarisation between the two major political blocs, Chahed is attempting a partnership with Ennahdha, knowing he would not be able to lead the government without their backing. Likewise, Essebsi has been seeking (in vain) support from the Islamist party which would allow him to remove Chahed from office.

"[Ennahdha] changed their alliance to go with Chahed," the 91-year-old president told local media.

"Ennahdha is now manoeuvring to stick to some kind of compromise, still. But with whom and at what cost?"

In rethinking the terms of the agreement, the moderate Islamist bloc seems to be striking an alliance with the newly formed pro-Chahed bloc - named the National Alliance - mainly made up of independents and former members of Nidaa Tounes, Machrouu Tunis and the Free Patriotic Union.

That said, there are divisions within this group on who to build consensus with, whether with the current prime minister or an emerging leader in the secular camp.

"We are open to work with the new parliamentary group backing the prime minister, and we stay open to other parties," Driss said. "I think the trend is now grouping in the largest possible way as there's a shared idea of coexistence and cooperation in the political elite."

The Nidaa Tounes leadership, for its part, welcomed the split with Ennahdha as a golden opportunity to shuffle its party ranks and please its popular base before next year's elections. It also means departing from a perceived political imbalance it says has benefited Ennahdha.

There have also been resignations from the liberal parliamentary bloc - with a splintering into various factions - partly driven by opposition to the alliance with the Islamists and by opposition to the attempt to remove Chahed from power.  

This decline in Nidaa Tounes' parliamentary power and popularity has naturally played in Ennahdha's favour.

We paid a high price for being in alliance with Ennahdha, but we are back again

Now with 42 seats, Nidaa Tounes is no longer the largest party - or even the second-largest - with the National Alliance now becoming the number two faction in parliament, with 43 seats, and Ennahdha still in dominating with 68 seats out of 217.

"We paid a high price for being in alliance with Ennahdha, but we are back again," noted an optimistic Toubal for Nidaa Tounes. "Now our responsibility is to ally with all those parties who share our same progressive national project ahead of 2019 elections."

Ennahdha's Driss says their former coalition partner has been aiming to distance itself from the Islamist group with a view to winning the next elections - unless Ennahdha agrees to back the demand for Chahed's resignation.

Meddeb, meanwhile, thinks the Islamists are well-placed to win as largest political force in the next general election, given the present fragmentation inside the secular parliamentary bloc and Ennahdha's ambition to sweep the elections.

As parliamentarians shift loyalties, parties are merging, and alliances are in formation, a new power balance is emerging.

What the political landscape will look like nearer election time next year remains unclear. Meanwhile, the course of transition remains fragile; the country is struggling to advance with the hoped economic reforms, and the economy is largely paralysed.

Any remaking in the balance of power post-divorce between the two ruling parties may cause more divisions across the political spectrum - however, it is not likely to threaten severe political chaos, which all the political actors are keen to avoid.

Alessandra Bajec is a freelance journalist currently based in Tunis. 

Follow her on Twitter: @AlessandraBajec