* Authorities deny poisoning allegation
* Furore arises days before Sunday's election
* Vote may entrench pro-Western/pro-Russian split
By Alexander Tanas
CHISINAU, Feb 21 (Reuters) - Two opposition leaders on Thursday accused Moldovan authorities of poisoning them, drawing a rapid denial from the ruling party, just days before a parliamentary election that threatens to tip the east European country back into crisis.
Maia Sandu and Andrei Nastase, who have joined forces to campaign against the ruling Democratic Party ahead of Sunday's vote and accuse its leadership of rampant corruption, said doctors had discovered heavy metals in their blood.
"Suspicions arise, and against the background of the attitude of the current government to those whom they think are dangerous, this case should be taken seriously," Sandu said.
"The authorities want our deaths," Nastase added.
A spokesman for the pro-Western Democratic Party rubbished the allegation and said "strange accusations are heard in the last few days and are becoming more and more fantastic."
"Unfortunately, the election campaign in Moldova has sometimes exceeded common sense," said the spokesman, Vitalie Gamurari.
The election pits the Democratic Party, which heads the current government and denies corruption allegations, against the Socialists, who favour closer ties to Russia.
Nastase and Sandu's ACUM bloc oppose both these main parties and on Thursday also signed a pledge not to enter into a coalition with them in case of a hung parliament.
The election threatens to entrench a split in the country between pro-Western and pro-Russian forces at a time when concerns over corruption and democracy have soured its relations with the European Union.
Opinion polls suggest no party will win an outright majority, which could set the scene for months of coalition talks or another election.
Moldova, one of Europe's poorest countries, which is squeezed between Ukraine and EU member state Romania, plunged into political crisis in 2014-2015 after $1 billion was pilfered from three banks.
The scandal tarnished the image of pro-Western forces in the country, which the European Parliament last year declared "a state captured by oligarchic interests".
The EU has also frozen aid to Moldova after a local court struck down the victory of Nastase in the Chisinau mayoral race on a technicality.
The election campaign has been dogged by worries that the election will not be free and fair.
President Igor Dodon, a former Socialist party leader, on Tuesday told his supporters to be ready for mass protests if the Democratic Party tried to cling on to power.
"The current authorities are ready to do anything to save power," he said. "On February 24, everyone should be able to make their choice freely. I know that people are bribing, intimidating, threatening ... Do not be afraid. Take the money and vote as your conscience tells you."
Facebook Inc said last week it had disrupted an attempt to influence voters in Moldova.
Government employees were linked to some of the activity, the California-based social media company said. Authorities in Chisinau denied knowledge. (Writing by Matthias Williams, Editing by William Maclean)
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