The request was delivered to the protector's Cape Town office by DA Chief Whip Douglas Gibson at 1pm yesterday.
Earlier this week, Gibson said it was "expected" of President Thabo Mbeki to refer Lekota's conduct to the Public Protector, in accordance with the Executive Members' Ethics Act.
If Mbeki failed to do this, the DA would itself approach the protector, Gibson said.
Last Thursday, Parliament's joint ethics committee sanctioned Lekota for failing to comply with the provisions of the parliamentary code of conduct.
Committee chairman Luwellyn Landers said the committee found Lekota was negligent in making incomplete disclosures of his interests.
"The committee, however, found that there was no evidence that the minister wilfully withheld information with the intention to mislead Parliament," Landers said.
The committee recommended that Speaker Dr Frene Ginwala issue a written reprimand to Lekota, and that he be fined one week's (seven days) salary.
This translates into a fine of R11 485 for Lekota, as a Cabinet minister.
The committee's report was tabled in the Assembly this week, and the matter is expected to be considered soon.
After last Thursday's meeting, Lekota's spokesperson, Sam Mkhwanazi, said the minister regretted the negative publicity the issue had caused to Parliament and the African National Congress.
Lekota would abide by and respect the committee's findings, as well as the National Assembly's decision on the recommendations made, Mkhwanazi said.
The same day, Gibson said the committee's findings and recommendations did not dispose of the matter entirely because Lekota was not only an MP, he was a minister.
"A disarming and charming admission of negligence might just suffice for an MP; for a minister it is not enough.
"Ministers are subject to the Code of Ethics for Ministers, which set more stringent requirements," he said. – Sapa-AFP.