Mr Khan, in Lahore, confirmed that the movement would not take the form of a traditional political party, and suggested its launch might take place within two weeks.
His wife also acknowledged that Mr Khan may have been targeted in the bombing that killed six people on Sunday in the out-patient department of his cancer hospital in Lahore. According to newspaper reports, the bomb went off at a time when he should have been at the hospital.
Mrs Khan said her husband plans to make good the damage to the Shaukat Khanum Memorial Cancer Hospital and Research Centre, estimated at $1m (pounds 650,000).
The blast happened only a day after Mr Khan, a critic of Pakistan Prime Minister Benazir Bhutto's government, said he was consulting aides about launching a new political party.
Mr Khan said the bomb was intended to frighten him into giving up his social welfare aims but declined to say who could have carried out the attack. His wife described the bombing as "a big setback", but said he would try to rebuild the department. "There's no other hospital like it," she said. "The country needs it."
Mrs Khan, who left for Pakistan yesterday after spending the Easter holiday with her family in Britain, said it was too early to be sure whether the bombers aimed to kill her husband. "I gather he was meant to be there at around midday," she said. "It's fairly easy to target a person in Pakistan. There is very little security at the hospital. If someone had wanted to assassinate him I think it would have been fairly easy to do so."
Asked whether she and her husband would now be stepping up their personal security, she said: "It is a relaxed environment there at the hospital ... The last thing on our minds up until now is that someone is going to blow up the out-patients department. So up until now we have had very little security."
Mrs Khan said the Princess of Wales, who visited the hospital in February to help raise funds, was upset by the bombing; Mrs Khan, and her parents, Sir James and Lady Annabel Goldsmith, had joined Princess Diana for lunch on Sunday.
"[The Princess] was as horrified as all of us," she said. "Diana was concerned for Imran ... she rang him and offered her condolences."
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