South Sudan's main party has said it will boycott¹ this week's elections in most of northern Sudan, citing voting irregularities and security fears.

南苏丹主要政党称，因选举违规和安全问题，将不会参加北苏丹大部分地区本周举行的选举。

The SPLM said it would only contest the election in two northern states

The Sudan People's Liberation Movement (SPLM) said it would not participate in the parliamentary and municipal（市政的） polls in 13 of the 15 northern states.

The SPLM has already withdrawn² its candidate from the presidential poll.

The elections beginning on Sunday are supposed to be Sudan's first multi-party vote since 1986.

President Omar al-Bashir has threatened to cancel an independence referendum（公民投票权） due in January for the already semi-autonomous（自治的，自主的） south, should the SPLM boycott the poll.

'No delay'

The SPLM serves in a national coalition³ with President Bashir, after joining a unity⁴ government in 2005, as part of a peace deal ending a two-decade civil war.

The party said it would still contest the elections in its southern stronghold（要塞，大本营） , as well as in the northern states of Blue Nile and South Kordofan.

The SPLM secretary general, Pagan Amum, said the partial boycott was to protest about insecurity in war-torn Darfur and alleged⁵ election rigging.

Many opposition⁶ parties have decided⁷ to partially⁸ or totally boycott the elections for the same reasons, says the BBC's James Copnall in the Sudanese capital Khartoum.

One major opposition party, Umma, is still deciding whether to participate.

Earlier on Tuesday, Sudan's National Elections Commission insisted the vote would go ahead as planned on Sunday, Monday and Tuesday.

There would be "no delay," Hadi Mohammed, a senior official in the body, told reporters after following talks with US special envoy⁹ to Sudan, Scott Gration.

The ruling National Congress Party (NCP) of President Bashir, who is wanted for alleged war crimes in Darfur, insists the elections will be fair.

"When they realised that the NCP was going to win, they decided to say that there is fraud," Mr Bashir told a rally on Tuesday, reports AFP news agency.

Last week, the SPLM announced the withdrawal¹⁰ of its presidential candidate Yassir Arman, a key challenger to President Bashir.

With no strong challenger, Mr Bashir, who seized power in a bloodless coup¹¹（政变，妙计） in 1989, looks set for a comfortable win, say analysts¹².

Some 1.5 million people died in the conflict between the mainly Muslim north and the south, where most people are Christian¹³ or follow traditional beliefs.