Khuong Sreng dismisses allegations that the government providing free bus rides for people during Khmer New Year is a tactic to buy votes.
The Cambodian Labour Confederation is permitted to celebrate Labour Day.
Several confederations and unions will celebrate International Labour Day next week.
Interior Minister Sar Kheng warns government would take legal action against CNRM.
Phnom Penh City Hall says that strikes and protests increased last year.
Phnom Penh City Hall building will be open to the public for one day next week as part of Heritage Day.