The register of MPs' interests was presented to Parliament's joint committee on ethics and members interests last week.
Motshekga "must take a harder line with Members of Parliament (MPs) who do not meet deadlines for the declaration of their interests," Democratic Alliance Chief Whip Watty Watson said in a statement.
"Considering Motshekga also missed the 23 August deadline, he must not allow this to cloud his judgement on this issue."
The committee's report, tabled in Parliament on Wednesday, contained the names of 69 MPs who missed the deadline for disclosure.
Fifty of the MPs were from the African National Congress. The DA, the African Christian Democratic Party and the Freedom Front Plus were the only parties to meet the original deadline.
The register is released once a year and lists gifts to MPs and their business interests, including directorships, property ownerships and shareholding in companies.
This allows the public, media and civil society to monitor potential conflicts of interest which may arise from MPs' gifts and business activities.
MPs who failed to meet the deadline for declarations showed contempt for the committee's work and undermined accountability and transparency, Watson said.
The DA welcomed the decision to publish the names of errant MPs, but would write to the ANC Chief Whip to call for appropriate disciplinary action against those who had not submitted declarations in due time, he said.
"In addition, I will ask the ANC Chief Whip to set an example and maintain discipline amongst parliamentarians. He should not be part of the problem."
The register revealed at least a dozen members of the National Assembly and National Council of Provinces who appeared to own absolutely nothing.
They included long-serving Deputy Environment Minister Rejoyce Mabudafhasi.
She had entered "nothing to disclose" in her declaration of shares and other financial interests, sponsorships, benefits, travel, land and property, and pensions, among others.
Several ministers received some portfolio-appropriate gifts.
Communications Minister Dina Pule was sent 38 bunches of flowers and Energy Minister Dipuo Peters received a "demo wind turbine", a "solar light" and a "glass nuclear power plant model".
Former defence minister Lindiwe Sisulu was given an "antique compass" by the Chief of the SA Navy, and Finance Minister Pravin Gordhan declared a R350 "stress ball" and a "facial hamper".
Congress of the People MP Tozamile Botha declared she had stakes in 62 entities, including real estate, construction, general trading, debt collection, and hotel businesses. – Sapa