(Adds comment by U.N. chief Ban Ki-moon)
By Amy Sawitta Lefevre
BANGKOK, Jan 10 (Reuters) - Thailand's government on Friday played down talk of a military coup ahead of a planned "shutdown" of the capital next week by protesters trying to overthrow Prime Minister Yingluck Shinawatra and said life would go on much as normal.
Foreign Minister Surapong Tovichakchaikul said it was alarmist of the U.S. embassy to advise its citizens on Friday to stock up on two weeks' supply of food and water ahead of what protest leaders say will be a prolonged siege of Bangkok.
"Maybe they worry too much ... People will live their normal life. Don't be afraid of things that will happen because we try to control the situation," he said.
Demonstrators led by former opposition politician Suthep Thaugsuban aim to paralyse the capital for between 15 and 20 days by blocking seven main intersections, causing gridlock in a city clogged with traffic at the best of times.
The turmoil is the latest episode in an eight-year conflict that pits Bangkok's middle class and royalist establishment against the mostly poorer, rural supporters of Yingluck and her brother, former premier Thaksin Shinawatra.
U.N. Secretary-General Ban Ki-moon said on Friday that he had spoken with Yingluck and the leader of the opposition Democrat Party, Abhisit Vejjajiva, during the past few days in a bid to help them bridge their differences.
"I am very concerned that the situation could escalate in the days ahead, particularly next Monday ... when protestors said they will shut down Bangkok," Ban told reporters. "I urge all involved to show restraint, avoid provocative acts and settle their differences peacefully, through dialogue."
The protesters want to suspend what they say is a fragile democracy destabilised by Thaksin, whom they accuse of nepotism and corruption. They want to eradicate the political influence of his family by altering electoral arrangements in ways they have not spelt out, along with other political reforms.
Thaksin was ousted by the military in 2006 and sentenced to jail in absentia for abuse of power in 2008 but he still looms large over Thai politics, the dominant force behind his sister's administration from his self-exile in Dubai.
The authorities say they will deploy more than 14,000 troops and police on Monday, including police at the main airport, to maintain order in the streets.
Rumours of an impending coup have intensified. The army has staged or attempted 18 coups in 81 years of on-off democracy, but it has tried to remain neutral this time and its chief, Prayuth Chan-ocha, has publicly refused to take sides.
The government has repeatedly played down talk of a military intervention but said on Friday if there was one, it would counter it. "We already have a plan ...," said Surapong, offering no elaboration.
He said the government would operate during the shutdown from backup locations at the national police headquarters and at an army base in the north of Bangkok.
He said Yingluck would not relocate her government to other provinces. She heads a caretaker cabinet after calling a snap election in December. The opposition Democrat Party has said it will boycott the election.
Polling is set for Feb. 2, but the Election Commission said on Friday the government should consider pushing back the date.
It said some candidates had been unable to register in 28 districts in the south - a stronghold of the anti-Thaksin protesters - and that could delay the reopening of parliament if there were not enough lawmakers elected to meet the quorum of 95 percent of the seats in the house.
The protesters have rejected the election, demanding that the government step down to be replaced by an unelected "people's council".
The courts may play a part in forcing the government out, as legal cases are building up against Yingluck and her allies.
The country's anti-corruption body pressed charges on Tuesday against 308 lawmakers, mostly from her Puea Thai party, for trying to make the Senate a fully elected chamber, which a court ruled illegal in November.
Puea Thai officials have expressed concern the government's enemies might be plotting a judicial coup and accuse the courts of bias. They say they are alarmed at the speed with which such matters are being processed, in contrast to cases against opposition figures, including protest leader Suthep, that have languished in the courts for years.
"They (the protesters) want to grab power unconstitutionally ... but the Constitutional Court ruled that there was no case (to answer against that)," Deputy Prime Minister Pongthep Thepkanchana told foreign media on Friday.
"In this Constitutional Court there are some judges ... who had an explicit role against the government in 2006," he added, referring to when Thaksin was toppled.
The judiciary has intervened several times in the past to throw out governments linked or allied to Thaksin. (Additional reporting by Michelle Nichols at the United Nations, Editing by Alan Raybould, Clarence Fernandez and Andrew Hay)