The Government has suspended the passports of at least 15 National Super Alliance (NASA) leaders on Tuesday.
Among them are Siaya Senator James Orengo, businessman Jimi Wanigi, strategist David Ndii, Mombasa Governor Ali Hassan Joho and former Machakos Senator Johnston Muthama are among those who have been asked to hand over their passports.
News of the suspension of David Ndii's passport had emerged earlier on Tuesday.
A letter signed by Maj. Gen (Rtd) Dr Gordon Odemo Kihalangwa, Director of the Department of Immigration, surfaced online.
It read in part: "Pursuant to Section 31 (1) (2) of the Kenyan Citizenship and Immigration Act 2011, you are hereby notified that passport number C051258 which is in your possession remains suspended forthwith.”
The leaders have 14 days to hand over the passports to the authorities, failure to which they will become null and void.
Unconfirmed reports indicate that opposition leader Raila Odinga's passport has not been affected by the move.
Article 12 (1b) of the Constitution guarantees the right of every Kenyan to hold a passport and "may be denied, suspended or confiscated only in accordance with an Act of Parliament that satisfies the criteria mentioned in Article 24 (of the Constitution)".
The suspension of travel documents come as the latest move in a crackdown on opposition leaders that followed the swearing in of Raila as the People's President on January 30.
Judge Luka Kimaru of the Milimani Law Courts on Tuesday ordered the release of National Resistance Movement (NRM) General Miguna Miguna and stated that the police were detaining him illegally.