A US federal appeals court has lifted a block on construction of a large ballroom and underground complex at the White House, allowing work to continue until at least 5 June. The US Court of Appeals for the District of Columbia issued the stay after the Trump administration challenged a ruling by District Judge Richard Leon, who had halted above-ground construction on the grounds that the project lacked congressional approval and proper regulatory sign-off. The project — which involves demolishing the White House East Wing (built in 1902) to make way for a privately funded, $400 million venue with capacity for 1,350 guests — has been the subject of a lawsuit by the National Trust for Historic Preservation, which argues the administration bypassed required planning and legislative processes.