Gallup, the public opinion polling agency, will stop tracking presidential approval ratings after almost nine decades, a spokesperson confirmed.

As Donald Trump continues to closely scrutinize polling of his popularity, and publicly lambast media companies that report on unfavorable numbers, Gallup insisted its decision was “solely based on Gallup’s research goals and priorities”.

Trump’s second-term approval rating fell to 36% in December, which is among the lowest ever recorded by the company. The US president started his second term with an approval rating of 47%.