A guide to the provinces where the fighting may be fiercest.

Siem Reap

6 seats

Though Siem Reap has long been a ruling-party stronghold (the CPP won four of six seats here in 2003, increasing their spoils to five of six seats in 2008), if recent opposition rallies are anything to go by, the province could be one of the more competitive domains in this election.

An estimated 100,000 supporters turned out to greet Sam Rainsy there Wednesday, possibly matching the number that turned out in Phnom Penh, the party’s traditional base, for his return from self-exile.

Rainsy’s rhetoric in Siem Reap aimed to exploit local sentiments that “Vietnamese” businesses have too much control over the province’s lucrative tourist trade.

Analysts also say that living standards in Siem Reap, which remains one of the Kingdom’s poorest provinces, will be a key issue.

Kampong Speu

6 seats

Despite being a relatively small province and one dominated by the CPP at the last national election, observers point to Kampong Speu as an area where competition between the two main parties will heat up in this election.

The now-merged SRP and HRP together won 34 per cent of total votes in last year’s commune elections, to the CPP’s 56 per cent, up from the 28 per cent of votes won between them in the 2008 national election.

In those same commune elections, parties other than the CPP were able to win 33 per cent of seats.

Old rivalries will also come to a head in Kampong Speu, with Pen Sovann, Cambodia’s first prime minister after the Khmer Rouge and a historic rival of Hun Sen, placed first on the CNRP ballot.

Hun Many, the premier’s youngest son and the first to run for office, is listed as a CPP candidate.

A successful election for him would signal the first step towards a new generation of CPP leadership.

Phnom Penh

12 seats

The Kingdom’s capital, worth a sizeable 12 seats, will always be an electoral battleground. In 2003, half the seats were won by the SRP, with the CPP and Funcinpec taking four and two seats respectively.

With Funcinpec’s 2008 electoral wipeout, the CPP took seven seats to the SRP’s five in 2008.

This election, observers are tipping the major parties to be in a dead heat for Phnom Penh, though some say the CNRP might have a slight edge.

Party heavyweights will also face-off in the capital, with CPP chairman/Senate president Chea Sim and former Phnom Penh governor Kep Chuktema running for the ruling party, while influential lawmaker Son Chhay and party spokesman Yim Sovann are on the CNRP ballot.

Kampong Cham

18 seats

The most populous province, with a mammoth 18 seats on offer, and home to many of the Kingdom’s sizeable Muslim Cham minority, Kampong Cham was one of the most contested provinces in the 2012 commune elections (where non-ruling parties managed to win 40 per cent of the total available seats).

The CPP won 11 seats here in 2008, but analysts expect the opposition to make further inroads this election. In a sign of the province’s clout, CNRP deputy president Kem Sokha and National Assembly president/CPP honorary chairman Heng Samrin are both running here as candidates, as is Foreign Minister Hor Namhong.

Funcinpec’s president, Princess Norodom Arun Rasmey, is also running in Kampong Cham and hopes to retain the seat won in 2008 by a fellow royalist from the now-defunct Norodom Ranariddh Party (with which Funcinpec recently merged).

Prey Veng

11 seats

Although the CPP picked up seven of the 11 seats available in Prey Veng in 2008 on the back of Funcinpec’s decline, the province was the most contested in the 2012 commune elections.

In last year’s election, the HRP and SRP polled a total of 210,209 votes to the CPP’s 258,716 votes. Now that the opposition parties have merged into the CNRP, Prey Veng could shape up for a major showdown.

Given that the province is located on the border with Vietnam, observers say the CNRP’s anti-Vietnamese rhetoric will appeal to Prey Veng voters.

Kandal

11 seats

With 11 seats on offer, Kandal province, home to Prime Minister Hun Sen’s National Assembly seat, has been labelled by some observers as “the province to watch” this election.

In 2008, the SRP held on to three seats in the province. Its current CNRP alliance partner, the HRP, also picked up a seat amid the Funcinpec implosion that saw the royalists lose all three of their seats in the province.

The opposition will be hoping to claw back some of the CPP’s seven seats in Kandal come Sunday, but with Hun Sen’s reputation on the line, the ruling party is likely to do all it can to remain dominant.

ADDITIONAL REPORTING BY DAVID BOYLE AND ABBY SEIFF