The discipline watchdog of the Communist Party of China (CPC) has pledged it will continue to curb official extravagance and other malpractices during the upcoming May Day holiday.

Xu Chuanzhi, a senior official with the CPC Central Commission for Discipline Inspection (CCDI), vowed "zero tolerance" and "severe penalties" on violators in an interview posted on the agency's website.

Spending public funds on feasts and private tours, official car use infringements, gift-giving, and holding excessively extravagant wedding ceremonies or funerals are "diseases" which are prone to happen during holidays, Xu said.

The May Day holiday will last from May 1 to 3 this year.

Party committees at various levels should alert officials to discipline themselves, their families and subordinates during key holiday periods, Xu said.

In case of serious violations, both violators and their leading officials will be held responsible, he said.

Before traditional holidays in the past year, such as the Mid-Autumn Festival, the National Day Holiday, New Year and Spring Festival, the CCDI had issued circulars urging officials to refrain from luxurious banquets and gift-giving.

Since the implementation of the CPC's "eight-point" anti-bureaucracy and formalism rules, 42,666 people had been punished nationwide by the end of March.

The rules were introduced by the central leadership in late 2012. They order CPC officials to reduce pomp, ceremony, bureaucratic visits and meetings.

"Though problems of harmful work styles have reduced in its brazen form after more than one year of the campaign, they are being carried out in a more concealed way," Xu said.

Lavish feasts are now being served in dining halls, households and rural restaurants. Some officials are frequenting more secretive private clubs and gifts are given via online payment platforms, according to Xu.

"Innovating ways to find out and effectively solve such concealed forms of violations are the difficulties we face," Xu said.