Growth in the massive U.S. services sector picked-up in December, according to the Institute for Supply Management. Meanwhile, job openings hit a six-month high in November, according to the Labor Department.

The companies argued in a lawsuit announced on Monday that Biden violated the Constitution by blocking the merger via a sham national security review that deprived the companies of their right to a fair process.

Nippon Steel and U.S. Steel are filing a federal lawsuit challenging the Biden administration’s decision to block a proposed nearly $15 billion deal for Nippon to acquire Pittsburgh-based U.S. Steel