Refusing to be "intimidated" by a slew of "ancient" corruption charges, Pakistan president Asif Ali Zardari has warned that forces who were earlier allied with dictatorship were now plotting to undo democracy and destabilise his government through judicial process.

"I have spent almost 12 years in prison on trumped up charges never proven, even by a court system manipulated by dictators and despots. But like Benazir, I refuse to be intimidated," Zardari wrote in an op-ed piece in the Wall Street Journal.

Some of these forces who were allied with dictatorship in the past now hope that the judicial process can undo the will of a democratic electorate and destabilise the country, Zardari, who is facing the heat following the Supreme Court's annulment of the controversial corruption immunity granted to him and some 8000 other officials, said.

"A litany of ancient charges of corruption—the modus operandi of past plots against every democratically elected government in Pakistan—now threatens to undermine the legitimacy of our government," he says in the article, published on the second death anniversary of the assassination of his wife, Benazir.

"My ministers, my party, leaders of other parties and thousands of civil servants across our nation will defend themselves in the courts if necessary," he says, adding that he was unfazed by the legal fight ahead.

"So let the legal process move forward. Those of us who have fought for democracy against dictatorship for decades do not fear justice; we embrace it," he said.Zardari said Pakistani forces have reclaimed Swat and Malakand from the militants and rehabilitated the displaced persons back into their homes.

"We have taken the fight against militants to other areas, including South Waziristan in our Federally Administered Tribal Areas, and to our major cities, and we will win this war against them.

"We will not let militants violently impose their political agenda on the people. Political ownership of the war against terrorism rests with the people of Pakistan for the first time," he said.