KIEV (Reuters) – Ukraine’s opposition leader Viktor Yanukovich headed for a slender victory on Monday in a bitterly contested presidential election but rival Yulia Tymoshenko refused to concede.

Yanukovich, 59, a beefy ex-mechanic who wants better ties with Moscow, claimed victory and called on Tymoshenko, 49, to resign as prime minister.

With almost 80 percent of votes counted, election officials gave Yanukovich 48.78 percent and Tymoshenko 45.56 percent. But Tymoshenko’s camp offered a “parallel count” that saw her edging out her rival.

The official results appeared to cap a remarkable comeback for the rough-hewn Yanukovich, cast as the villain of the 2004 Orange Revolution when street protests overturned results that initially gave him victory in an election tainted by fraud.

The outcome could also see the country of 46 million people tilt back toward former Soviet master Russia after five years of bitter infighting and a sliding economy turned Orange euphoria into frustration and disappointment.

Both candidates pledged integration with Europe while improving ties with Moscow, but Tymoshenko is seen as more pro-Western.

Yanukovich is unlikely to pursue membership of NATO, an ‘Orange’ goal that infuriated neighboring Russia.

Accusing Yanukovich of cheating, Tymoshenko’s team said they had counted 85 percent of votes and that she was leading by 0.8 percent, presaging a possible messy legal challenge.

Each side accused the other of fraud, but Tymoshenko stopped short of repeating a threat she made last week to call people out onto the streets if she believed the election was unfair.

“I think that Yulia Tymoshenko should prepare to resign. She understands that well,” Yanukovich said in a television interview. Exit polls put him three to four points ahead.

Tymoshenko was the co-architect of the 2004 revolution with pro-Western President Viktor Yushchenko, but their relationship quickly soured.

Looking stern before reporters, the fiery former gas tycoon urged her team to “fight for every result, every document, every vote.” The tone was moderate, and analysts said they doubted Tymoshenko could stage a repeat of 2004.