Revised passport regulations in Taiwan allow its citizens to attach stickers advocating "Taiwan independence" on their passport covers, which observers said shows a growing rift on the island and will jeopardize cross-Straits relations.

Taiwan's "Legislative Yuan" voted to delete a clause that stickers are prohibited from being attached to passport covers, while Taiwan's "Ministry of Foreign Affairs" said citizens with modified passports will not be asked to provide their personal information when they enter or exit Taiwan from Thursday, the Central News Agency reported on Wednesday.

In 2015, Taiwanese pro-independence supporters started a campaign to redesign their passport covers with stickers that read "Republic of Taiwan" over the original "Republic of China."

"Allowing citizens to attach stickers on their passport cover is an extremely childish decision, and shows that Taiwan's democracy is headed for populism," Chiu Yi, former Kuomintang (KMT) legislator, told the Global Times on Thursday.

"Taiwan's administrative organs continue to be run by the KMT, yet the 'foreign ministry' has already followed the Democratic Progressive Party's (DPP) decision," Chiu said, adding that it is possible that more incidents related to "pro-Taiwan independence" may take place once the DPP takes over.

Taiwan's "Bureau of Consular Affairs" under the "Ministry of Foreign Affairs" and the ministry could not be reached for comment as of press time.

Allowing the pro-Taiwan independence stickers on passport covers will cast a shadow on cross-Straits relations, making it difficult to repair weak mutual trust between the two sides, said Chang Ya-chung, an international relations professor at National Taiwan University.

Attaching stickers to passport covers may cause problems for Taiwan citizens who travel abroad, experts said, adding that some Taiwanese have been denied entry to some regions and countries over their altered passport covers.

Taiwan's representative office in the US advised Taiwan citizens not to place "Republic of Taiwan" stickers on their passports when entering the US, warning that their entry may be refused, the China Post reported in December 2015.