Activist Okiya Omtatah has given Central Bank of Kenya (CBK) seven days ultimatum to remove founding President Jomo Kenyatta's portrait from Kenya notes and coins.
The constitution stipulates that portraits or images of individuals are not to be used on currency and notes and coins should only bear images that depict or symbolise an aspect of Kenya.
"The constitution decrees that notes and coins issued by CBK may bear images that depict or symbolise Kenya or any aspect of Kenya but shall not bear the portrait of any individual,"Omtatah said.
In a letter dated September 14, the activist told CBK governor Patrick Njoroge that he has seven days to comply with the law, failure to which he will move to the court.
"The CBK should publicly declare that it will, with immediate effect, begin withdrawing all unconstitutional currency notes and coins from circulation," he said.
The activist said the notes and coins bearing image of first President should immediately be replaced with those that do not bear the image of any individual.
"Failure on your part to respect, uphold and defend the constitution as required will necessitate our recourse at the bank's sole risk as to cost and other consequences, to the constitutional and human rights division, for orders to compel your compliance."
In 2016, CBK boss Njoroge said printing notes without Kenyatta's image would cost the taxpayer Sh18 billion.
Appearing before the Senate Finance Committee, Njoroge said they expected to roll out the new currencies this month.
He said the CBK failed to meet the August 2015 constitutional deadline for rollout following the cancellation of the tender.