For more than two weeks, two leading Pakistani opposition figures have mobilised their supporters behind a single goal - to topple the government of Prime Minister Nawaz Sharif.
Imran Khan and Tahir ul-Qadri have been holding sit-ins in Islamabad's so-called Red Zone, home to parliament and the prime minister's residence.
But on Saturday night, the protesters pushed through police lines and tried to march on to the prime minister's house.
Police responded with tear gas and rubber bullets. The sit-ins are the greatest challenge to Nawaz Sharif's current term in power. And come despite historic elections that brought him to office last year.
The vote was heralded as Pakistan's first democratic transfer of power.
As the political crisis deepens, we look at who is behind the protests? And what role Pakistan's powerful military is playing?
Presenter: Nick Clark
Waj Saeed Khan - national security editor for Pakistan's Geo TV.
Mosharraf Zaidi - former Pakistani foreign affairs adviser and education campaigner.
Jibran Nasir - current affairs TV Host on Pakistan's Dawn News. Once ran for office as an independent against Imran Khan's candidate in Karachi.
Source: Al Jazeera