(Adds monk; protesters' plans for Sunday, Monday)
By Nick Macfie and Khettiya Jittapong
BANGKOK, March 1 (Reuters) - A green oasis in downtown Bangkok was slowly beginning to resemble a tent city on Saturday, a day after anti-government protesters said they would clear camps blocking key intersections and congregate in the park instead.
The protesters have blocked some streets since mid-January in their bid to push out Prime Minister Yingluck Shinawatra and eradicate the influence of her brother, ex-premier Thaksin Shinawatra, seen as the real power in Thailand.
Protest leader Suthep Thaugsuban's supporters are to move to Lumpini Park, where many protesters already sleep in tents near an established protest stage on the edge of the Silom financial district.
The tents are slowly filling up the park, most under the shade of trees and blue awnings and next to boating lakes, with washing lines strung between branches.
"We will stop closing Bangkok and give every intersection back to Bangkokians. We will stop closing Bangkok from Monday," Suthep told supporters on Friday.
"But we will escalate our shutdown of government ministries and Shinawatra businesses."
Protesters plan a big cleaning-up day on Sunday before opening roads on Monday but at least two affiliated groups plan to stay put at their protest sites, including one led by a controversial Buddhist monk.
"I was angry with Suthep's announcement," monk Luang Pu Buddha Issara told Reuters. "We have lost blood and lives and for what? To end it all now?"
Protest numbers have dwindled amid attacks on various camps with grenades and guns. Three people were killed when a grenade was thrown into a busy shopping area near one camp on Sunday.
In total, 20 people have been killed in protest-related violence in Bangkok since Nov. 30 and three in the eastern province of Trat.
The threat of violence has taken a toll on tourism in the capital, even though most areas have been unaffected, including the old part of town by the river and the Khao San Road backpacker district frequented by westerners, many of whom, regardless of age, dress like hippies.
"Business is good here. As good as ever. There is no politics here," a restaurant worker said on Friday.
DEBATE PROPOSAL REJECTED
Labour Minister Chalerm Yoobamrung on Friday rejected a Suthep proposal for a television debate with Yingluck, who media on Saturday quoted as saying was ready to die for democracy.
"Yingluck is the legitimate leader of the country and Suthep is a man with warrants for his arrest who heads an illegal movement. The prime minister should not talk to Suthep," Chalerm said.
"Suthep is only proposing negotiations, even though he dismissed them before, because protest numbers are dwindling."
The crisis is hurting the economy, with confidence and domestic demand both down. Data on Friday showed factory output fell 6.41 percent in January from a year earlier.
The crisis broadly pits Bangkok's middle-class and southern opposition supporters, backed by the royalist establishment, against the largely rural supporters of Yingluck and Thaksin.
Thaksin was toppled by the army in 2006. The military has tried to stay above the fray this time but Yingluck is still facing multiple challenges from the courts, which threw out two governments allied to Thaksin in 2008.
Yingluck called an election for Feb. 2 to try to end the latest crisis but it was disrupted by the protesters.
The Election Commission will try to hold polls on Sunday in five provinces where voting was not completed. Election re-runs planned for April in other provinces have been suspended pending a court decision on procedures.
The protesters want to set up a "people's council" of unspecified worthy people to force through political and electoral changes before a new general election is held, hoping that will stop parties loyal to Thaksin from winning. (Additional reporting by Amy Sawitta Lefevre; Editing by Simon Cameron-Moore)