House Republicans filed a long-threatened lawsuit Friday against the Obama administration over unilateral actions on the health care law that they say are abuses of the president’s executive authority.

The lawsuit — filed against the secretaries of the Health and Human Services and Treasury Departments — focuses on two crucial aspects of the way the administration has put the Affordable Care Act into effect.

The suit accuses the Obama administration of unlawfully postponing a requirement that larger employers offer health coverage to their full-time employees or pay penalties. (Larger companies are defined as those with 50 or more employees.)

In July 2013, the administration deferred that requirement until 2015. Seven months later, the administration announced a further delay , until 2016, for employers with 50 to 99 employees.