A new electronic entry card for Taiwanese visitors to China has sparked protests and a political backlash despite Beijing touting the move as a way to make travel easier.

China introduced the card on Monday after announcing it in June, but Taiwanese authorities say they were not told of the roll out.

The island's Mainland Affairs Council -- its top China policy decision-making body -- said there had not been "proper communication" in advance of the launch.

"The way they are doing this is irrespective of Taiwan and has hurt the feelings of Taiwan people," it said in a statement.

Taiwan's Premier Mao Chi-kuo also said he was "extremely dissatisfied" adding that he had been given no prior notice of the move.

Around 20 members of the anti-China Taiwan Solidarity Union (TSU) threw eggs and let off firecrackers outside Beijing-friendly president Ma Ying-jeou's residence Tuesday night in protest.

"The cards may benefit some Taiwanese businessmen and students in China, but the policy is aimed at downgrading Taiwan to the level of Hong Kong and Macau (both semi-autonomous regions of China)," TSU spokesman Chang Chao-lin told AFP Wednesday.

Self-ruling Taiwan split from China at the end of a civil war on the mainland in 1949, but Beijing still sees the island as part of its territory awaiting reunification.

It does not recognise Taiwanese passports.

The card had already been on trial for visitors to the southern Chinese province of Fujian for two months.

China says it is part of wider measures to reduce barriers with Taiwan.

Visitors used to need two documents -- a paper visa and an entry permit -- to enter China.

Now they just need the electronic card, which will replace the old paper document and be valid for five years.

Ties between China and Taiwan have improved markedly since 2008 after Ma came to power promising to beef up trade and tourism links.

But recently public sentiment has once again turned against closer ties with Beijing, with voters saying trade deals have been agreed in secret and have not benefited ordinary citizens.

Tensions flared earlier this year when Beijing rejected Taipei's bid to become a founding member of a China-led Asian Infrastructure Investment Bank (AIIB).

There was also anger over its decision to inaugurate a new flight route near Taiwan and in response to a military drill carried out against a backdrop that resembled Taipei.