By Johan Ahlander and Helena Soderpalm
STOCKHOLM (Reuters) - A political crisis gripped Sweden on Wednesday after opposition parties called for a no confidence vote they would almost certainly win over a botched outsourcing deal in which sensitive material was transmitted abroad.
The vote, targeting ministers of three departments who failed to raise the alarm over short cuts during implementation of the contract, would undermine the government's already brittle authority and make fresh elections a distinct possibility.
The minority left-green government said Prime Minister Stefan Lofven would hold a press conference on Thursday at 0800 GMT, without commenting further.
The center-right opposition is seeking to boot out the infrastructure, defense and interior ministers - respectively Anna Johansson, Peter Hultqvist and Anders Ygeman - for failing to take action during the outsourcing of IT services for the Swedish Transport Agency in 2015.
Lofven admitted on Monday that, as a result of the way the contract was handled, his country and its citizens were exposed to risks by potential leaks of sensitive information.
The government said in 2015 that the contract process - won by IBM Sweden - was speeded up, bypassing some laws and internal procedures.
IBM Sweden said it never commented on relations with clients.
The center-right opposition Alliance - comprising the Moderate, Centre, Liberal and Christian Democrat parties - announced earlier on Wednesday it would call the no confidence vote, without specifying when.
"It is obvious the three ministers have neglected their responsibility. They have not taken action to protect Sweden's safety", Centre party leader Annie Loof told a news conference.
The legislature is in recess but the opposition parties will submit their motion to the speaker, who will then summon legislators for a vote within 10 days.
Including the nationalist Sweden Democrats, whose leader Jimmie Akesson told Reuters his party would support the motion, the opposition have a majority in parliament, meaning the vote is likely to pass.
Losing three key ministers would be a further body blow to Lofven's government, which has already lost votes in parliament.
After the opposition's budget bill got more support than the government's in 2014 he called a snap election, which he retracted after a compromise was reached.
"He has shown he can do the unexpected," said Jonas Hinnfors, political scientist at Gothenburg University, who did not rule out snap elections or the government resigning.
"The alternative is to stay on severely wounded, which in itself is very problematic for the government... This is a crisis for the government and the credibility of the prime minister."
Domestic markets remained unfazed, however, with the crown little changed against the euro.
"The political situation in Sweden generally has a very small effect on both (interest) rates and exchange rates," said Carl Hammer, economist at SEB.
"I think the best explanation to that is that we have a triple A rating, sound public finances, a low national debt and all that. The macroeconomic situation is stable."
The Transport Agency said on Monday it had no indications sensitive material had actually ended up in the wrong hands, but Lofven said the government had started an investigation into what had happened, promising to tighten laws for handling of sensitive material.
He said on Monday that Johansson, the infrastructure minister responsible for the Transport Agency, had not passed information on to him. Johansson had on Sunday blamed one of her former state secretaries for not informing her about the issue.
Sweden is due to hold parliamentary elections in September 2018 which a snap election would not replace, meaning it now faces the prospect of two ballots inside a year.
(Reporting by Helena Soderpalm, Johannes Hellstrom and Johan Ahlander; editing by John Stonestreet)