More than two years after the army aborted a dismal interregnum and released from jail the leaders of the country's two rival political dynasties, the politics of hate and attrition grind away in Bangladesh. The thanks go mainly to the personal vendetta of the prime minister, Shaikh Hasina, one of the two leaders, against the other, Khaleda Zia.

On November 13, Zia was evicted from her home of nearly 30 years in Dhaka's cantonment area. The move triggered a hartal, a protest strike called by Zia's opposition Bangladesh Nationalist Party (BNP). Violence broke out between her supporters and those of Shaikh Hasina's Awami League (AL). The country's third political force, the army, has backed the High Court's eviction order. Shrewdly, Shaikh Hasina has allocated the vast plot surrounding Zia's home for housing for the families of 57 military officers killed in a mutiny early last year, soon after the AL swept to power.

The eviction is part of the League's mission to break the BNP's back. It is obsessed with airbrushing from history the legacy of the political dynasty founded by Zia's late husband, General Ziaur Rahman, hero of Bangladesh's war of independence against West Pakistan in 1971.

In February the government renamed Dhaka's Zia International Airport after a respected Sufi saint. It has decided to "reprint" the 1972 constitution to reflect a landmark Supreme Court ruling in July which, among other things, declared null and void the rule of various military governments, including Zia's, following the assassination in 1975 of Bangladesh's founding father, Shaikh Mujibur Rahman. (Shaikh Mujib, as he is usually known, is the father of Shaikh Hasina.) In October a court issued an arrest warrant for Zia's younger son in a money-laundering case. Four corruption cases stand against Zia, while 13 cases against Shaikh Hasina, filed during the army interregnum, have been withdrawn.

Minority

Yet the BNP was in a shambles even before the recent onslaught. The party has just 30 seats in a 300-strong parliament, which it boycotts. It is split: Zia can count only on the support of a minority of BNP leaders. Meanwhile, the leaders of the BNP's main ally, Jamaat-e-Islami, Bangladesh's largest Islamic party, have all been jailed. They stand accused of alleged atrocities during the country's war of secession, and face possible execution. The alliance has hurt the BNP's reputation, particularly internationally, says Moudud Ahmad, a former prime minister and Zia's lawyer. Yet the BNP needs Jamaat-e-Islami's electoral support.

Zia's only hope is that people will get fed up with rising prices, power shortages and the open encouragement by Shaikh Hasina's government of the kind of predatory capitalism not seen since, well, Zia's rule in 2001-06.

At some point, Zia appears to calculate, mass adulation will attach to her eldest son and heir apparent, Tarek Rahman, now in British exile. Yet Rahman, who left army custody with a snapped spinal cord in 2008, is the symbol of Zia's kleptocratic rule. He is loathed even among the BNP's leaders.

Meanwhile, Shaikh Hasina's vendetta has the support of the Indian government, with whom Bangladesh's relations are much improved. The end to Zia's political dynasty has become almost a tenet of national security for India, which sees her family meddling in India's domestic affairs.

This month Rahman's right-hand man told investigators that the Pakistan embassy in Dhaka and the United Liberation Front of Asom, a militant group fighting for an independent homeland for ethnic Assamese in India's north-east, paid the BNP (for which, read Rahman) and Bangladeshi spooks some $10m (Dh36.7 million) for the secret transshipment to Indian insurgents of ten truckloads of arms.

Western governments also oppose Rahman's return. They supported the thinly veiled army coup in January 2007, which prevented the BNP from stealing an election. The coup also brought in a crackdown on fringe groupings of Islamist extremists courted by the former BNP government. Continuing the crackdown is a centrepiece of AL policy.

Despite the government's sliding ratings, popular support for Shaikh Hasina's clan dwarfs that for Zia's. And with such a tailwind, it is extraordinary how the League remains stuck in a divisive politics based on personal grievances that go back nearly four decades. Time, you might think, to get on with governing