The PTI was formed in Lahore on April 25, 1996 by its chairman, cricketing legend and politician Imran Khan Niazi.
PTI has fielded candidates from 248 NA seats — out of these 136 seats are from Punjab, 46 from Sindh, 38 from Khyber Pakhtunkhwa, 14 from Balochistan, 11 from Fata and three from Islamabad.
Despite a strong campaign, the party failed to win a majority at the centre in the 2013 general elections and sat on the opposition benches with 32 seats. The party, however, formed a government in Khyber Pakhtunkhwa (KP) after an alliance with Jamaat-i-Islami.
In 2008, PTI boycotted the elections. It held the position that an elected parliament had little to no meaning under a president in military uniform. Pakhtunkhwa Milli Awami Party, National Party and a few other smaller parties also boycotted polls that year.
PTI managed to get one seat in the National Assembly, won by Khan himself.
PTI did not win a single seat in the 1997 elections, which were its first.
The party has been a vocal opponent of former president Pervez Musharraf's decision to participate in the United States-led 'war on terror' in the aftermath of 9/11.
The party has also advocated dialogue with the Taliban, and has for the most part been against taking military action against the militants.
The PTI has also opposed drone attacks by the US in Pakistan's tribal areas, and regards them as a reason behind the rise in militancy in the region.
It staged a 126-day-long sit-in in 2014 in Islamabad's Red Zone, saying ruling PML-N had won in the 2013 polls through rigging and that an investigation had to be held to address it. The party demanded the resignation of then prime minister Nawaz Sharif. The sit-in, that lasted nearly five months, concluded when Imran Khan called it off in December 2014 following the Army Public School massacre in Peshawar.
The party was at the forefront of demanding Nawaz's resignation in 2016 after the Panama leaks. The Panama Papers showed that Nawaz's children Mariam, Hasan and Hussain “were owners or had the right to authorise transactions for several (offshore) companies”. The leaks led to calls for accountability into the financial dealings of the Sharifs. Following an investigation into Nawaz's assets, he was disqualified by the Supreme Court in July 2017 for failing to declare a receivable salary as an asset in his 2013 nomination papers.
The party launched the billion tree tsunami initiative in KP, and planted one billion trees in the province in a bid to conserve the environment.
Former PTI leader Javed Hashmi alleged that Khan had been "working hand-in-glove with the forces of establishment". He had also alleged that PTI's 2014 dharna was in fact the brain child of ex-ISI chief Ahmed Shuja Pasha, adding that Khan had been in regular contact with ex-army chief Kayani and Pasha during the sit-in. Hashmi quit PTI during the dharna and the party calls him a disgruntled ex-member whose words should not be needed.
Despite PTI's public position against corruption, the party itself has been accused of receiving funds illegally from overseas Pakistanis. The petition against PTI in this regard was filed by one of its dissident founding members Akbar S. Babar and is ongoing in the Election Commission of Pakistan since 2014.
Senior PTI member and former KP chief minister Pervez Khattak has also been accused of using state machinery for personal use. However, party leadership has not addressed the allegations.
Earlier this year, senior PTI leader Jahangir Khan Tareen was disqualified for being 'dishonest' under Article 62(1)(f). Imran Khan had also been accused of failing to declare an offshore company, however, he was found not guilty. The court said Khan was "not liable" to declare Niazi Services Ltd in his 2013 nomination papers as he was not a shareholder or a director of the company.
On a few occasions, female members of the PTI have accused the leadership of gender bias. Naz Baloch quit the party in July 2017 claiming only male members were given importance and women party workers were kept at a distance while the youth was restricted only to social media. A more serious allegation was levelled by Ayesha Gulalai, who accused Imran Khan of sexual harassment and claimed that "the respect of women is not in tact in the hands of Imran Khan and the men who surround him".
Another influential PTI leader, Ali Ameen Gandapur was accused in 2017 by then PTI member Dawar Khan Kundi, of facilitating eight people who were allegedly involved in stripping and parading a teenage girl in Dera Ismail Khan and filming her. However, Imran Khan claimed the allegations against Gandapur were false and announced that he would expel Kundi from the party.
Soon after the Senate elections of 2018, PTI was accused by its KP coalition partner Jamaat-i-Islami of not voting honestly in the polls for the Upper House and instead of following orders "from the top".
Despite the party's strong support for dialogue with militant groups, it has been mostly silent on army action in the tribal areas in the past few years. It supported the National Action Plan formulated in the wake of the APS attack as well as the establishment of military courts.