This seems to be occurring because of Tsarukian's withdrawal from a commitment the three parties made in February not to compete against each other in the May 2012 parliamentary elections, and to back Sarkisian for a second term in the presidential elections the following year.
With just four months to go, the HHK has finally announced it will participate alone in the May elections.
That announcement put an end to months of mutually contradictory statements and speculation about whether the three parties aligned in the ruling coalition would form an election bloc.
What new political alignments might emerge in the run-up to the May ballot remains unclear, however.
Tensions between the HHK and BH first surfaced in the fall of 2009, fuelled by persistent rumors that BH might quit the coalition to facilitate a political comeback by former President Robert Kocharian, who is close to Tsarukian.
Protocols And Political Comebacks
Both the HHK and BH sought to downplay that speculation. In February 2011, they signed a formal protocol together with the third coalition partner, National Security Council Secretary Artur Baghdasarian's Orinats Yerkir (Country of Law) party, on jointly participating in the May 2012 parliamentary elections and supporting Sarkisian's bid for a second term in the presidential election the following year.
Last September, however, Kocharian confirmed that he might attempt a political comeback in the absence of a tangible and stable improvement in economic and social conditions, or if unspecified groups lobbied for his return to big-time politics, but only if he were convinced he could "radically improve the situation."
Tsarukian immediately defended Kocharian's right to return to the political arena.
Despite a veiled warning by Prime Minister Tigran Sarkisian (no relation to Serzh) and a wave of arrests of BH activists on criminal charges in November, Tsarukian declined formally to reaffirm his commitment to the February protocol.
A BH spokeswoman finally said last month that the party has no plans to form an alliance with the HHK for the May 2012 ballot.
Denials And Insinuations
At the same time, she denied that there had been any "political pressure" to do so.
Similarly, Orinats Yerkir leader Baghdasarian denied on December 13 that any of the three parties had proposed an electoral alliance.
One can only guess about which of the three parties dealt the death blow to the supposed parliamentary-election alliance, and how it will impact on their respective election chances.
But circumstantial evidence indicates that BH either broke ranks, or miscalculated the HHK's patience with its efforts to increase its popularity by underscoring its independence from the HHK.
One leading BH member implicitly accused the HHK on January 27 of engineering the resignation of no fewer than 58 of its members, presumably in retaliation.
One of the defectors has since been named to head the police department in the southern town of Ararat.
Whatever precipitated the decision that the three parties would run independently, it will be greeted with triumph by former President Levon Ter-Petrossian, now head of the Armenian National Congress (HAK), an umbrella group that unites some two dozen small extra-parliamentary parties and movements.
Inspired by the Arab Spring, the HAK launched a series of protests in February 2011 with the aim of extracting major concessions from Sarkisian, who Ter-Petrossian insists defeated him in the March 2008 presidential election because the ballot was rigged. These concessions included the scheduling of early elections.
While President Sarkisian rejected that demand, the authorities did accede to others, including the release of opposition supporters jailed following the postelection clashes in Yerevan in March 2008 and a formal "dialogue" with the authorities.
The HAK suspended those talks in August, however, to protest the arrest of one of its youth activists.
One of the leitmotifs of Ter-Petrossian's criticism of the Armenian authorities in the run-up to the 2008 presidential ballot was the role and pernicious influence of wealthy businessmen, several dozen of whom not only control economic monopolies but represent the HHK in parliament.
In an astonishing U-turn in November, Ter-Petrossian affirmed the HAK's readiness to cooperate with BH if that party "sincerely wants to leave the coalition and fight for truly fair and legal elections."
He also defended Tsarukian against what he termed smear campaigns launched by the authorities.
Not all of the 20-odd small parties aligned under the HAK banner approved Ter-Petrossian's offer, however.
Some argued that the HAK risked losing popular support by openly wooing BH.
Hrant Bagratian, who served as prime minister under Ter-Petrossian from February 1993 to November 1996, subsequently explained that Ter-Petrossian's objective was not to form an alliance with BH but to prevent an election bloc composed of BH and the HHK.
A member of the HAK's Political Council told RFE/RL on January 27 that 18 of its members have reached agreement on jointly participating in the May election. He did not specify whether they would seek to team up with other opposition parties.
Senior HAK members are confident the party will poll the minimum 5 percent of the vote necessary to win parliamentary representation under the proportional system.
Of the total 131 parliament mandates, 41 are for single-mandate constituencies and the remaining 90 are allocated according to party lists.
Opposition Parties Under Pressure
Many domestic observers likewise believe the HAK will win seats in the new legislature, together with the HHK and BH.
The two opposition parties represented in the current parliament may be hard-pressed to retain their current level of representation.
The Armenian Revolutionary Federation-Dashnaktsutiun (HHD), which has 16 parliament mandates, joined the ruling coalition in March 2008, but quit one year later to protest Sarkisian's overtures to Turkey.
Hrant Markarian of the HHD's governing bureau told journalists on January 26 that the party believes it will win seats in the new legislature, and is therefore disinclined to form an election alliance with any other party.
The Zharangutiun (Heritage) party, headed by U.S.-born former Foreign Minister Raffi Hovannisian, has seven parliamentary mandates.
Zharangutiun is currently in exploratory talks with the Free Democrats, a new grouping established last year by a handful of veteran Ter-Petrossian allies who quit the HAK under pressure.
They include a second former Foreign Minister Alexander Arzoumanian, who managed Ter-Petrossian's 2008 election campaign.
Relations between the HHD and Zharangutiun are strained. The two parties exchanged barbs last month after the HHD declined to back Zharangutiun's candidates for the vacant posts of parliament speaker and deputy speaker and voted instead for the HHK's nominees.