(Reuters) - The junior partner in Greece's ruling coalition will continue to support the government but there are limits to its support, a party spokeswoman said on Tuesday. The spokeswoman of the Independent Greeks Marina Chrysoveloni also ruled out joining a coalition government with two opposition parties. Prime Minister Alexis Tsipras faces a showdown with rebels in his own party furious at his capitulation to German demands for one of the most sweeping austerity packages ever demanded of a euro zone government.