Khan's party, at odds with powerful army generals, has been grappling with a military-backed crackdown that has gathered pace ahead of the February 8 vote.Â
The party, the Pakistan Tehreek-e-Insaf (PTI), alleges the military is trying to keep it out of the election race, a charge the army denies.
A party's electoral symbol on ballot papers is significant for voters to be able to identify its candidates in the south Asian nation of 241 million people, where most of the constituencies are in rural areas with low literacy rates.
Chief Justice Qazi Faez Isa announced the ruling in a live late-night telecast of the proceedings on the top court's website.
Stripped of the bat, PTI candidates will need to contest on individual symbols, which could confuse voters.
"This, by far, is the worst decision impacting million of voters," the party said in a statement, with its chairman, barrister Gohar Khan, announcing that its candidates will contest the election as independents.
The Election Commission of Pakistan had stripped the PTI of the symbol on the technical grounds that it had not held intra-party elections, a prerequisite for any political party to take part in the national poll.
The party had challenged that ruling in the top court.
The election campaign, delayed since November, has been a lacklustre race in an uncertain political environment, with Khan, 71, jailed and disqualified from contesting.
His main rival, former three-time prime minister Nawaz Sharif, has been cleared of all court cases and a lifetime ban to contest the polls.
