At a press event to mark one year until the census, the Bureau told reporters that it is ready for either decision.

"We have film that will be prepared for our printer for either decision that they make," associate census director Al Fontenot said, CNN reported. 

"For our electronic side of the Census, we have a plan where we have a switch that says answer the question, ask the question, don't ask the question," Fontenot said.

The public will have the option to complete the census online, over the phone or by post. Fontenot said: “We have successfully completed numerous tests to validate our systems and operations to support these innovations, while ensuring that respondent data remain confidential, and we are ready to conduct the most technologically advanced and accurate decennial census in our nation’s history.”

Supreme Court justices are set to hear arguments on the citizenship question on 23rd April, with a ruling due by the end of June. Fontenot said the print deadline for the census is 1st July.

The introduction of a citizenship question by the Trump administration has raised concerns that it could negatively impact turnout and representation in the decennial census, which is used to determine federal funding decisions. The question has not been included since 1950.

The addition of the question has been blocked by two federal judges in California and New York City, and criticised by various civil rights groups.

On Monday ( 1st April), US President Trump waded into the debate, tweeting that the census would be “meaningless” without the “all important Citizenship Question”.

Last week, the Census Bureau said it had enlisted technology companies to help it address the threat of disinformation campaigns and fake news it fears could disrupt the census.