But in an embarrassing twist for the prime minister, the army swiftly denied this, saying it had been specifically instructed by the government to step in.
Nawaz Sharif's efforts to end the conflict have repeatedly failed in recent days, leaving Pakistan in a dangerous deadlock with thousands of protesters massing outside parliament in a country that has seen a string of military coups.
Opposition leaders Imran Khan and Tahir ul Qadri announced late on Thursday that they would directly negotiate with army chief General Raheel Sharif.
Both men later held talks with the general. Mr Qadri has not commented on the discussions while Mr Khan said the army would act as a guarantor on one of his key demands, for an investigation into his accusations of fraud in an election last year.
Prime Minister Sharif, who is not related to the army chief, has emerged much weakened from the crisis, his already uneasy relationship with the military hitting new lows. He was toppled in a military coup in 1999 during a previous stint in office.
Addressing parliament on Friday, Sharif said: "The army did not ask to play the role of mediator, neither have we requested them to play such a role."
However, the army's press wing quickly tweeted: "[The army chief] was asked by the Govt to play facilitative role for resolution of current impasse, in yesterday's meeting, at [Mr Sharif's] House."