A spending deal, passed by the House of Representatives and then the Senate to avert a government shutdown, included almost $6.7bn for the census, and around $7.6bn for the Census Bureau overall.

The legislation means the final funding level for the census in 2020 is the same as the level set in a previous temporary spending bill in November.

It is $1.4bn more than that requested by the White House and $800m below the House-passed CJS Appropriations level.

The funding was welcomed by marketing research industry body the Insights Association. Howard Fienberg, vice-president of advocacy, said: "The certainty of necessary full-year funding for the 2020 census comes late in the game, with the counting about to begin, but better late than never."

Fienberg added: "Now, we actually have to count everyone. A decade of preparations and testing (and, thanks to funding shortfalls, a lack of testing in key areas) will come to fruition in America’s largest peacetime mobilisation. The Insights Association has lobbied hard to get us to this point because the marketing research and data analytics industry can't conduct representative research studies without the most accurate census data as a statistical benchmark."