Imran or Sharif: who wins today?

Cricket star-turned-politician Imran Khan is hoping to become Pakistan's prime minister after 20 years of being dismissed at the polls, as the country prepares to vote in a tense election pitting him against the party of jailed ex-premier Nawaz Sharif.

Khan, 65, has hailed Sharif's conviction on corruption charges this month as proof democracy is maturing in the  nation by finally holding its venal political elite accountable. Supporters of Sharif, whose party is now led by his younger brother, Shehbaz, argue his downfall was politically motivated and engineered by the army establishment.

Recent nationwide polls indicate a tight race, with Khan's party ahead on 30 percent in one survey, compared to 27 percent for PML-N. Sharif's party tops another poll with 26 percent compared to 25 percent for Khan's Pakistan Tehreek-i-Insaf (PTI).

In third place was the Pakistan People's Party of Bilawal Bhutto Zardari. The PPP could emerge as a coalition kingmaker if no party wins a majority, as many expect.

In 2013, the PML-N won 126 seats, while Khan's party came third with 28 seats.

Khan has banked on gains in the PML-N stronghold of Punjab, Pakistan's most-populous province that has 141 elected seats, for his path to victory, successfully courting many so-called "electables" - entrenched local power brokers who often hold sway over about a quarter of Punjab's seats.

Two new hard-right Islamist parties also may cut into the PML-N's conservative voter base.

However, the PML-N could reap a sympathy vote after Nawaz Sharif returned to be arrested on July 13 along with his daughter Maryam, leaving his cancer-stricken wife in a London hospital.

The PML-N has taken hope in another opinion poll focusing on Punjab only - Sharif's party had a lead of 51 percent to PTI's 30 percent, according to the IPOR Consulting survey conducted from April 15 to June 2.