Tens of thousands of government supporters massed on the outskirts of the Thai capital Saturday in a show of strength against those seeking to topple Prime Minister Yingluck Shinawatra, according to dpa. Followers of the United Front for Democracy against Dictatorship (UDD), better known as the red shirts, came from outer provinces to occupy a highway on the fringe of western Bangkok, as a warning of things to come. UDD organizers claimed that at least 300,000 people had signed up to join the rally that is planned to last until Monday. "Today we have come close to Bangkok," said UDD co-leader Kaugeow Phiaunphong. "We are ready to move into Bangkok if anything unconstitutional happens." The rally was organized to pressure the court system and the army against staging a judicial or military coup to install an unelected prime minister to rule the country. "The red shirts will come out if we have an unelected cabinet," said UDD senior leader Thida Tavornseth. "That may happen soon. Maybe by the end of the month." The Constitutional Court decided last week to proceed with an abuse of power case against Yingluck, for allegedly dismissing former National Security Council chief Thawil Pliensri in 2011 to pave the way for her relative, Priewpan Damapong, to become national police chief in a series of transfers. She was given 15 days to defend herself. If found guilty of breaching the constitution, Yingluck and her entire cabinet could face dismissal for approving Thawil's transfer. That could lead to the power vacuum which anti-government protesters have been seeking or the past five months. Anti-government protests since early November have been seeking to topple Yingluck and have an appointed premier preside over political reforms before any new elections. The opposition says it wants to curtail the continuing influence of her elder brother, fugitive former prime minister Thaksin Shinawatra, in national politics. Thaksin has lived abroad since 2008 to avoid a two-year jail term for an abuse of power conviction but is still regarded as de facto leader of the ruling party and the red shirt movement. Fears are rising that the sharply polarized crisis will erupt into armed civil conflict. "When they have a neutral prime minister, the red shirts will come out and fight," said Chaturon Chaisaeng, caretaker Education Minister. "And they will need to kill a lot of people. It will be a big conflict."