Mark Zuckerberg’s rival to Twitter will not launch in the EU on Thursday amid regulatory uncertainty about the service’s use of personal data. Sources at Meta, which owns Facebook, Instagram and WhatsApp, said regulations were behind the postponement of an EU launch, amid a series of clashes between the social media group and the bloc. It is understood that the main issue for the Twitter competitor, called Threads, is the implementation of the EU’s Digital Markets Act, which contains provisions on sharing user data across different platforms. Meta is awaiting further clarification from the European Commission, the EU’s executive arm, on how the legislation will be implemented before considering its next steps. Threads is still expected to launch in the UK and US on Thursday and is being advertised on Apple’s app store, which shows a service with a Twitter-like interface. Typing “Threads” into Instagram leads to a countdown timer that expires at 10am ET (3pm BST), implying a morning launch in the US. Elon Musk, who owns Twitter, has been quick to flag the amount of data that may be collected by Threads, pointing to the app store’s listing of the kinds of information that “may be collected”which includes “location” and “search history”. Musk wrote on Twitter “thank goodness they’re so sanely run”, a reference to a Meta executive who said last month that creators and public figures had expressed interested in joining a Twitter-like platform that was “sanely run”. However, Twitter’s own website acknowledges that the platform collects user data such as location, the device you use and interactions with other users’ content. Jack Dorsey, Twitter’s co-founder and backer of another rival service called Bluesky, posted a picture of Threads’ app store listing on Tuesday with the quip “all your Threads are belong to us”. Two recent rulings against Meta have created problems for the company’s operations in the EU. This week the European court of justice upheld the right for EU watchdogs to investigate privacy breaches in a ruling that said user consent was needed before using their personal data to target them with adverts. It followed an EU ruling in May ordering Facebook to stop transferring user data to the US, which could lead to the social media network shutting its European services. Threads is launching amid further upheaval at Twitter under Musk’s ownership, after the Tesla CEO introduced viewing limits for tweets at the weekend. A rival platform to Twitter, Bluesky, said it had paused sign-ups because of a jump in demand after the move, while another alternative, Mastodon, saw a surge. Twitter said on Tuesday it had been forced to impose viewing limits – 10,000 posts a day for verified accounts and 1,000 for unverified accounts – to counter spam and bot accounts that were plaguing the platform. It pointed to companies developing artificial intelligence programs that rely on publicly available information, such as posts on social media platforms, as one source of the vexatious accounts, stating that entities were “scraping people’s public Twitter data to build AI models”. It also said there were accounts “manipulating people and conversation” on the platform.