TEHRAN — If you are Iranian, much of your life for the past few years has depended on a messaging app called Telegram. It has become something of a parallel, but uncensored, internet.

Since 2013, Telegram has replaced email, chat, forums, blogs, news websites, e-commerce, social networks, dating services and, for many, even television. With Telegram, Iranians keep in touch with family and friends, read the news, shop, discuss soccer, babies, marriage and politics. It’s the best of Twitter and the most viral videos on YouTube. People use it to download music and films, and, of course, to flirt. They also use it to read speeches from the supreme leader, Ayatollah Ali Khamenei, who blasts out content over his official channel.

Part of the reason Telegram is so popular is it’s easy to use. Another reason is more political: Since the pro-reform protests in 2009, the hard-liners in Iran’s government, working through their allies in the judiciary and security services, have effectively blocked nearly all foreign-based blogging and publishing platforms, social media and messaging apps.

Now they want to do the same with Telegram. On March 31, Alaeddin Boroujerdi, a hard-line member of Parliament and the head of its National Security and Foreign Policy Commission, announced that Telegram would be blocked for security reasons by the end of April. “This was a decision made at the highest levels, and Telegram will be replaced by a domestic app,” Mr. Boroujerdi said. A few days later, Abolhassan Firouzabadi, secretary of the Supreme Council of Cyberspace, which was established by Ayatollah Khamenei in 2012, appended an unlikely economic case against Telegram, which had announced plans to launch its own cryptocurrency: “Telegram is seeking to turn the Iranian economy into an intermediary company, and that will destroy jobs such as in real estate and auto trading,” he said. (Telegram doesn’t plan to offer its cryptocurrency to countries that, like Iran, are under Western or United Nations sanctions.)