Nippon Steel and US Steel are suing the US government after their $15 billion deal was blocked on national security grounds by Joe Biden.
The two companies say the presidential power to sink the deal was improperly exploited for political reasons.
Court challenges to rulings like this have never succeeded, but the process could shed light on exactly how much politics played a part in the president’s decision; the merger was fiercely opposed by the head of the United Steelworkers, Dave McCall – who endorsed Kamala Harris.
The odd thing about Biden’s decision – leaving aside the snub to an ally – is that it appears to make little economic sense.
US Steel says that without the deal, it will not have money to invest in its older mills in Indiana and Pittsburgh, which are likely to close.