* Czech PM wants Kalousek to stay on as finance minister
* Main opposition party protests, appointment unclear
* Budget gap soars past full-year plan
(Adds budget gap, opposition rejection, background)
By Jan Lopatka
PRAGUE, May 4 (Reuters) - Leading Czech politicians wrangled over a new finance minister on Monday as the budget gap ballooned, highlighting the need to find a candidate to keep spending in check ahead of early elections planned for October.
The finance post has become a sticking point in a political crisis that toppled outgoing Prime Minister Mirek Topolanek halfway through the country's European Union presidency and cast the Czechs into limbo in the heat of the global economic crisis.
Parties have been nominating candidates for a new caretaker cabinet being formed by non-partisan Prime Minister-designate Jan Fischer, expected to lead the country to the early vote.
Topolanek, who resigned after a March no-confidence vote, nominated Finance Minister Miroslav Kalousek to keep his post after two other officials from the existing ministry fell by the wayside.
"The interim cabinet has one fundamental task, and that is the completion of an uneasy budget for the next year, and in that respect there were three names in play that would secure continuity," Topolanek told a news conference on Monday.
"I decided in favour of Miroslav Kalousek," Topolanek said.
But Jiri Paroubek, head of the leftist opposition Social Democrats, whose support is key for Fischer's cabinet to win confidence, said Kalousek was "unacceptable".
Data on Monday showed the budget deficit had doubled on an annual basis in April. It exceeded the full-year plan and looked set to reach 4.5-5 percent of gross domestic product for the full year. [
] [ ]
OPPOSITION SAYS NO
President Vaclav Klaus, expected to appoint Fischer's team on May 8, has in the past praised Kalousek and said he should stay on. Kalousek is a close ally of Topolanek, but he is a member of the junior ruling Christian Democrats.
Kalousek has hinted he may quit the party.
Fischer's spokesman was not available for comment, and it was not clear if the nomination could go through.
Like elsewhere in Europe, where falling growth has hit state revenues, the Czech budget deficit has overshot estimates.
The country's overall public sector fiscal gap is expected to triple this year as the economy shrinks by more than 2 percent, according to ministry estimates.
Kalousek has said spending cuts will be required this year and next to keep the central state budget gap, the main part of the overall fiscal balance, at 150 billion crowns.
That is nearly four times the originally approved 38.1 billion crowns originally planned for 2009 on an assumption of economic growth of 4.8 percent.
Earlier on Monday, data showed the January-April budget gap jumped to 55.7 billion crowns, from 28.1 billion a year ago. Overall revenues slipped 2.1 percent and spending jumped 5.4 percent as the economic crisis bit.
Markets, quiet due to a market holiday in London, showed little reaction to the news, with bonds steady and the crown ticking up to 26.57 per euro from 26.60. (Additional reporting by Jan Korselt; Editing by Michael Winfrey and Patrick Graham)