* Khan's PTI party planning mass protests on Wednesday
* Khan accuses Pakistan PM of corruption
* Pakistan military has history of staging coups
By Kay Johnson and Drazen Jorgic
ISLAMABAD, Oct 31 (Reuters) - Pakistani opposition leader Imran Khan on Sunday dismissed accusations his planned shutdown of the nation's capital could lead to a military coup, saying Prime Minister Nawaz Sharif "can't hide behind 'democracy in danger'" to quash protests.
Khan, a former national cricket hero, has vowed to bring a million people into Islamabad on Wednesday to paralyse the government and force Sharif either to resign or allow an inquiry into the "Panama Papers" revelations about his family's offshore wealth.
Sharif's ruling PML-N party has accused Khan's Pakistan Tehreek-e-Insaf (PTI) party of endangering democracy by attempting to draw Pakistan's powerful military into a political dispute - a sensitive issue in a nation where the army has a history of staging coups.
Reuters interviewed Khan at his plush home in the hills above Islamabad, where he says the police have him under virtual house arrest after the city banned public gatherings ahead of Wednesday's planned protest and arrested scores of PTI workers.
He dismissed claims he wants the army to topple Sharif, as it did when Sharif was in power in the 1990s, and said the protests aim to hold the prime minister to account for alleged corruption.
"How can a democrat want the military to come in?," Khan said. "He has to answer. He can't hide behind 'democracy in danger'."
Pakistan's military has repeatedly refused to comment on Wednesday's planned protests.
Relations between the PML-N party and the military soured earlier this month after a newspaper report about a top-level national security meeting angered the army, prompting the removal of one of Sharif's cabinet ministers blamed for the leak.
The tense relations, as well as the rowing between Sharif and Khan, have stirred unease and prompted newspaper editorial warnings that a descent into street chaos could trigger military intervention.
On Sunday, one of Sharif's closest allies, Planning Minister Ahsan Iqbal, wrote in the English-language The News newspaper that Khan was "willing to derail democracy for personal gains".
The attack adds to long-held suspicions by PML-N supporters that Khan is being used by the military in a power struggle with the civilian government, which has ceded control of key policy areas such as relations with India and Afghanistan to the military.
"I don't need the army," Khan said. "I'm doing what the opposition is supposed to do. Expose corruption, expose breaking the laws of the land ... It doesn't mean I'm asking the army to come in."
SHARIF "MESSED IT UP"
Khan said it is corruption, not protests, that threatens democracy.
"When you have people coming to power and looting the country, they actually weaken the democratic system because people lose faith in democracy, and when the army comes in they welcome them with sweets."
Khan blamed Sharif for the latest tensions between the government and the military, saying Sharif's allies leaked details of the security meeting to the Dawn newspaper.
"They messed it up," said Khan. "They have humiliated the army, they've exposed the army, they've ridiculed the army because of the (Dawn leak) - what have we got to do with it?"
The Oct. 6 Dawn article said top PML-N politicians confronted high-ranking military officials and called for the military not to interfere if civilian authorities tried to arrest members of anti-India militant groups such as Jaish-e-Mohammad and Lashkar-e-Taiba.
On Friday, Khan's supporters fought running battles with police in the city of Rawalpindi, close to Islamabad. Scores of PTI party workers have been arrested.
Khan has accused the police of brutality, and urged his supporters to lay low until Wednesday to avoid arrest.
FEARS OF INSTABILITY
Khan's latest challenge to Sharif's government is based on leaked documents from the Panama-based Mossack Fonseca law firm that appear to show the prime minister's daughter and two sons owned offshore holding companies registered in the British Virgin Islands and used them to buy properties in London.
Sharif's family denies wrongdoing.
Holding offshore companies is not illegal in Pakistan, but Khan insists the Sharif family money was gained by corruption. Khan, 64, said in May he used an offshore company himself to legally avoid paying British tax on a London property sale.
The ruling party has said it would take part in an investigation, but has rejected the opposition's formula focused on Sharif's family rather than making it broad based. Sharif's own name did not appear in the Panama Papers.
In 2014, Khan led a months-long occupation that paralysed Islamabad's government quarter after rejecting Sharif's decisive election win a year earlier.
The prospect of similar protests has hit the local stock market, stoking fears of political instability just as the sputtering economy was starting to rebound.
Khan said that unless Sharif agreed to his demands over the Panama Papers investigation, there was little the government could do to make him call off Wednesday's protests.
However, he sought to downplay his party's calls to "lock down" the city roads and paralyse the capital, something that prompted the authorities to ban all public gatherings.
Khan said his previous rallying cries for supporters to stop the government functioning were not a direct threat, but rather a prediction.
"When you see a million people in Islamabad, trust me, the city will shut down," said Khan. (Writing by Drazen Jorgic; Editing by Kay Johnson and Ian Geoghegan)
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