Seoul - South Korea's opposition parties are expected to reap an election bonanza from seething public anger over the government's mishandling of the ferry disaster as campaigning for next month's local polls opened on Thursday.
The 4 June polls are the first nationwide elections since President Park Geun-Hye took office 16 months earlier and are widely seen as a referendum on her performance.
Prior to the 16 April ferry disaster which left more than 300 dead and missing, the elections were seen as a walkover for her ruling Saenuri Party as many middle-of-road voters threw their weight behind the conservative party on hopes it would improve the sluggish economy.
But the disaster has swung the spectrum of opinion to the left and is likely to bring a ballot bonanza to the opposition New Politics Alliance for Democracy (NPAD), especially in pivotal Seoul and nearby Incheon.
Winning these cities is crucial for election victory.
Opinion polls by the three main television networks conducted from Saturday through to Monday put the opposition comfortably ahead of the ruling party in Seoul, slightly in the lead in Incheon and neck-and-neck in Gyeonggi province.
"The government's incompetence in handling the ferry disaster was exposed to public scrutiny for more than a month through TV and other media coverage as it failed to rescue a single life from the sunken ferry", Jeong Han-Wool, executive director of the Centre for Public Opinion Research at the East Asia Institute, told AFP.
"This has made the Park government vulnerable to attacks from the opposition so that the voters should deliver a stern judgement on it through the ballot boxes".
The 6 825-ton ferry carrying an estimated 476 people sank off the country's southwest coast.
As of Thursday morning, a total of 288 passengers have been confirmed dead, most of them students on an organised trip, with 16 others still missing.
Seoul key battleground
"I frankly admit that we will face enormous difficulties in the elections unless we come up with ways to inject new hope and courage in the people", Saenuri Party parliamentary floor leader Lee Wan-Koo told party campaign workers on Wednesday.
His opposition NPAD counterpart Park Young-Sun said at a meeting with her party leaders on Wednesday that voters would send a "strong signal that a government which cannot protect the lives of people and children has no place to exist".
In battleground of Seoul, mayor Park Won-Woon of the NPAD faces a challenge from Chung Mong-Joon of the ruling party.
A victory for Park, a popular former pro-democracy activist, over the business tycoon who once served as Fifa vice chairperson is expected to bolster Park's presidential hopes.
The Seoul mayorship is widely seen as a stepping stone to the presidency after former mayor Lee Myung-Bak was elected president in 2002 thanks to his career as the top administrator of Metropolitan Seoul.
Up for grabs in the 4 June elections are 17 provincial governor and metropolitan mayoral posts, 789 city council seats, 226 local administrator posts, 2 898 local council seats and 17 education superintendents.