PML-N Vice President Maryam Nawaz on Tuesday demanded that PTI Chairman Imran Khan provide proof to back his claim of his party members receiving threatening phone calls from unknown quarters, and urged him to reveal the identities of "Mr X and Mr Y" he often mentions during his speeches.

According to a Dawn editorial on September 9, the former prime minister claims the two individuals, understood to be from national security institutions, are leading an effort to overthrow the coalition government in Punjab. Imran has claimed that they are calling PTI and PML-Q lawmakers and either tempting them with bribes or coercing them to change their allegiances.

Imran repeated his allegations about the two in Monday's Chakwal rally and called on the people to threaten them back.

Talking to the media in Islamabad on the topic, Maryam said: "What is X and Y? If there is proof then bring it forward."

She acknowledged that the PML-N had levelled similar allegations in the past but claimed to have also provided proof in addition to mentioning their names.

"The one on whose behest calls were being made yesterday is today saying 'my members are receiving calls [themselves]'. What about when you were responsible for calls to people? We received calls and threats too but we faced them."

Regarding his comments about Mr X and Mr Y during Chakwal's address, Maryam said that if Imran himself did not have the courage to reveal their identities "then what lesson are you giving to the nation to call them out and threaten them".

Maryam also addressed media reports of Imran's frustration with his party members for allegedly having contacts with the establishment behind his back, and questioned whether the PTI chief had himself informed the party of his own "secret meetings".

She alleged that Imran had meet former army chief Raheel Sharif during the PTI's 2014 sit-in as well. "Tell your party to do only what you yourself do. This can't happen that you call out someone in rallies and fall to their feet in the darkness of night," Maryam added.

To a question about whether Imran still continued to be the "blue-eyed child" of any institution, Maryam said: "That someone whose blue-eyed child he (Imran) is do not actually consider him to be so."

Regarding the Islamabad High Court quashing the terror charges against the PTI chief in the case over his controversial remarks against a female judge, Maryam said regardless of whatever sections were applied to him, "he is convicted every time because he has done this (comments against the judge) in front of the world and it doesn't need to be proved."

"He is a bully and adopted this method to mock, threaten and clear his way whenever in a difficult situation," she added.

The PML-N leader said the court should discourage Imran's attitude as it was "not good for the country, nation and institutions".

Maryam termed the Punjab government an "illegitimate government" and said it would come to an end someday.