St.-Sgt. Gilad Schalit would have been released from the Armored Corps on Tuesday along with seven of his friends, if he were not held captive by Hamas in Gaza. Bound to silence by the terms of their service, these seven soldiers, who were all drafted on the same day as Gilad and served with him until his capture, have not been able to speak or advocate publicly for his return until now. On Tuesday, as soon as they shed their khaki uniforms, they plan to become activists in pursuit of the release of the 21-year-old, who is still believed to be alive. "We know that any of us could be there instead of him," they wrote in a letter addressed to Prime Minister Ehud Olmert and Defense Minister Ehud Barak, which they plan to give to the two leaders immediately upon their release from mandatory service. Under the slogan: "We were released today, when will Gilad be?" the soldiers plan to march from the Tel Hashomer induction center to the Defense Ministry in Tel Aviv to present their letter to Barak. Afterward, they plan to march to the city's Kikar Rabin to meet with Gilad Schalit's parents, Noam and Aviva, around 8 p.m. In their letter they explain to Barak that when they were drafted they believed the IDF would turn the world upside down to bring them home alive and well. Schalit had faith in this as well, they said. "Only last Wednesday, the prime minister fulfilled his moral obligation to the Goldwasser and Regev families" and with great bravery negotiated with the enemy just to give peace to the families of the two slain reservists by returning their bodies, says the letter. "But Mr. Olmert," it goes on, "somewhere in a basement in the South, there is still one more debt that has to be paid. This debt is still alive, and he is waiting day-by-day, hour-by-hour to be released. This debt has a name and a face, it is Gilad Schalit. He has parents; Noam and Aviva. Do not allow him to be returned in a coffin." Among those who plan to join the soldiers in their battle is their former commander, Yoav Belkes, 28, of Beersheba. These soldiers fighting on behalf of their friend believe in the army and want to continue to serve, said Belkes. But as someone who continues to perform reserve duty, he said he was worried about the impact of the failure to return Schalit on the army. The soldiers were not trying to dictate the terms of his release, they were merely insisting that he must be returned and warning of the consequences of refusing to do so because the price was too steep, he said. "If they do not return him because the price is too high, soldiers will hesitate to go on missions," Belkes warned. Gilad was a "quiet soldier" and very connected to his friends. He was a good listener who was always there for them, and now his friends wanted to be there for him, Belkes said. Belkes often finds himself ruminating about Gilad and the kind of situation that he must be in. "Imagine yourself in his place. Would you survive? I try to imagine what he is feeling, but it is hard," he told The Jerusalem Post on Sunday. The soldiers are joined in their campaign by a grassroots mothers' group that has been working of behalf of Schalit for the last month. On Wednesday, at an event in Tiberias with teens from the Kibbutz movement, they plan to release a new song penned by singer David Zigman specifically for Schalit called, "Let the sun shine." Outside of Israel, Schalit's cause was picked up by former hostage Ingrid Betancourt who was freed earlier this month after more than six years of captivity at the hands of the Revolutionary Armed Forces of Colombia, or FARC. At a rally in Paris on Sunday she spoke out on behalf of prisoners held throughout the world, including Nobel Peace Prize laureate Aung San Suu Kyi, who is under house arrest in her native Myanmar, and Schalit. AP contributed to this report.