More than 20,000 Israelis demonstrated in Tel Aviv, Jerusalem and other places across the country late on Saturday in fresh protests against the spiralling cost of living, media reports said. The numbers were well below the more than 300,000 who demonstrated earlier this month calling for "social justice" and a "welfare state," organisers admitted, blaming renewed tension with the Palestinians. Since mid-July, Israel has been gripped by a rapidly growing protest movement demanding cheaper housing, education and health care. "Security problems have always existed in Israel. They will not stop our struggle," student union leader Itzik Shmuli told the demonstration in Tel Aviv, calling for a "million-man march" in a week's time. Noam Shalit, the father of Israeli soldier Gilad Shalit kidnapped in the Gaza Strip in 2006, was the guest of honour at the Tel Aviv rally on the occasion of his son's 25th birthday. He called on the government to "pay the price needed to bring Gilad home or resign." Although the middle class and students are the most militant, opinion polls show up to 88 percent of the population supports their protests, the largest in Israel's history. Under pressure, Prime Minister Benjamin Netanyahu has set up a commission to look into the issues and make proposals within a month.