US President Donald Trump has asked the Supreme Court to allow him to continue building a $400m (£295m) ballroom at the White House without congressional permission.

The emergency application comes one week after an appeals court ordered construction to stop until Congress approves, upholding a ruling won by the National Trust for Historic Preservation, which sued the administration last year.

In the latest filing, US Solicitor General D John Sauer asked that work be allowed to continue while the administration appeals the stop-work order, which he called “dangerous”.

Trump has long argued the White House lacks a large event space and that building one is vital for national security.

Last week’s appeals court decision does not take effect until 21 August, when ballroom construction will have to cease unless the Supreme Court grants the emergency application.

Sauer said in the filing on Friday that work on the project is 65% done and not granting it would amount to “construction-by-injunction”.

“With the dangerous injunction poised to take effect for the first time on August 21, its stop-work mandate is even more flagrantly inequitable, if not impossible,” he wrote.

Sauer added that “forcing the president to come hat-in-hand to Congress so the people’s house is safe gives the legislature dangerous leverage”.

Trump’s ballroom project has been the subject of a legal battle since October, when the administration demolished the East Wing of the White House to begin construction without congressional approval.

Soon after, the National Trust for Historic Preservation filed a lawsuit arguing that the project was unlawful because it began without a legally required review, which also includes public comment and approval by entities such as the National Capital Planning Commission.

The president and the government’s lawyers have argued that in addition to the ballroom to host events, the project also includes military facilities, including bomb shelters and centres for medical treatment.

The administration has also argued that the ballroom is being constructed without any taxpayer money and is fully funded by private corporate donations – meaning that Congressional approval is not required.

The White House ballroom project is part of Trump’s broader effort to remake Washington’s cityscape, which has also included the renovation of the Lincoln Memorial Reflecting Pool and a planned “Arc de Trump” in the style of the Arc de Triomphe in Paris.

The Trump administration has faced allegations in all the projects that it sidestepped required review and public-comment processes – a charge the president denies.