India, June 30 -- US President Donald Trump has thrown the future of a landmark, bipartisan housing package into deep uncertainty, calling the sweeping legislation "a big yawn" and threatening to withhold his signature unless lawmakers attach strict new voting restrictions.

The unexpected executive pushback sets up a high-stakes standoff with a nearly unified Congress, which just days ago passed the historic affordability bill by overwhelming, veto-proof majorities. The sudden executive friction has blindsided lawmakers from both parties who had celebrated the bill as the most significant federal effort to tackle the nation's housing crisis in decades.

The gridlock centres on the 21st Century ROAD to Housing Act, an ambitious piece of l...